Raeguard Pid Manual

Transcript

RAEGuard PID FGM-1000 Series Photoionization Detector Transmitter Operation & Maintenance Manual p/n 033-4001-001 Rev B READ BEFORE OPERATING This manual must be carefully read by all individuals who have or will have the responsibility of using, maintaining, or servicing this product. The product will perform as designed only if it is used, maintained, and serviced in accordance with the manufacturer’s instructions. CAUTION To reduce the risk of electric shock, turn off power before removing the lamp housing cap and PID sensor for service. The lamp housing cap provides an electrostatic shield. Never operate the unit when the cap is removed. Remove the lamp housing cap and sensor block only in an area known to be NON-HAZARDOUS. WARNING! The calibration of all newly purchased RAE Systems instruments should be tested by exposing the sensor(s) to known concentration calibration gas before the instrument is used or put into service. For maximum safety, the accuracy of the RAEGuard PID should be checked by exposing the sensor(s) to known concentration calibration gas. AVERTISSEMENT! La calibration de toute instruments de RAE Systems doivent être teste en exposant l’instrument a une concentration de gaz connue par une procédure dietalonnage avant de mettre en service l’instrument pour la première fois. Pour une sécurité maximale, la sensibilité du RAEGuard PID doit être verfier en exposant l’instrument à une concentration de gaz connue par une procédure dietalonnage. Contents 1 . General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Hazardous Location Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Operation of RAEGuard PID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1 Physical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Installation and Access Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . 6 Instrument Assembly Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Electrical Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Instrument Assembly Instalation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Sample Gas Plumbing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3 Display and Alarm Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 System Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Reading Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Alarm Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Access to Programming Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.4 Programming Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Calibration Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Zero Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Span Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.6 Correction Factors for Other Gases . . . . . . . . . . . . . . . . . . . . . . . . . 16 Programming the Correction Factor . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Modifying the Span Gas Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Manual Conversion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.7 Calibration With Other Compounds. . . . . . . . . . . . . . . . . . . . . . . . . 17 2.8 4-20 mA Current Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.9 Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3. Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4. Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.1 Cleaning the PID Sensor and Lamp. . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2 Pump Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.3 Filter Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5. Troubleshooting Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Appendix A: Correction Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Appendix B: Maximum Reading Capabilities and Indications . . . . . . . 29 Appendix C: Limited Product Warranty. . . . . . . . . . . . . . . . . . . . . . . . . 30 Appendix D: RAE Systems Contacts. . . . . . . . . . . . . . . . . . . . . . . . . . . 31 www.raesystems.com 1 1. General Information The RAEGuard PID is a fixed photoionization detector (PID) that measures a broad range of volatile organic compounds (VOCs). It operates on 9-36 VDC and provides an analog (4-20 mA) signal output in three ranges of 0.01 - 20.00 ppm, 0.1-100.0 ppm, and 1-1000 ppm isobutylene equivalent. Housed in an explosion-proof enclosure, the RAEGuard PID is equipped with a local digital display of the gas concentration and function keys for performing calibration. This flow-through sampling unit is ideal for remote sampling. Key Features • 4-20 mA analog output • Resolution of 0.01 ppm for precision model (range to 20 ppm) • Explosion-proof enclosure for hazardous environment applications • Magnetic key interface eliminates need to open explosion-proof ­enclosure when making operation parameter adjustments • Long-life 10.6 eV ultraviolet lamp with 3D sensor • Can draw sample from up to 100 feet (30 meters) • Sampling pump duty cycling for lamp self-cleaning • LCD and status/error LEDs • Operation at 9 to 36 VDC • Two dry contacts (<30V, 2A) for low and high alarm limits Applications • Waste water treatment plants • Marine and offshore oil wells • Refineries and petrochemical plants • Power plants • Pulp and paper industry • Solvent recovery systems • Painting and coating operations Hazardous Location Classification • UL • cUL • ATEX 2 RAEGuard PID Specifications Size Weight Detector Calibration Enclosure Rating Power Output Sampling Sampling Distance Display Response Time User Interface Temperature Humidity Dry Contacts Mounting Ranges (isobutylene equivalent) 5.0" L x 5.0" W x 4.5" H 127 mm x 127 mm x 115 mm 5.5 lbs (2.5 kg) 3D PID sensor std. 10.6 eV lamp 2-point field calibration US & Canada: UL, cUL Class I, Division 1 & 2, Groups B, C, D Europe: 0575 II 2 G Demko 03 ATEX 0229512 EEx d IIB T6 9 to 36 VDC max. 125 mA at 24V 4-20 mA w/12V compliance at 24V Internal diaphragm pump, >500 cc/min 100 feet (30 meters) maximum 7-segment, 4-digit screen with 4 colorcoded alarm LEDs 40 seconds to 90% of reading using isobutylene and 40% duty cycle Magnetically accessed keys for calibration -20º C to 55° C (-4º F to 131° F) 0-95% relative humidity (non-condensing) High and low alarm levels Max 30V, 2A each 2 holes, 5.25" (133 mm) from center to center 0.01 - 20.00 ppm, 0.1 - 100.0 ppm, and 1 - 1000 ppm (Ranges are different product models, and not user-selectable when operating unit.) This product may be covered by one or more of the following U.S. Patents: 5,393,979 5,561,344 5,773,833 6,225,633 6,313,638 6,333,632 6,320,388 www.raesystems.com 3 2. Operation of RAEGuard PID The RAEGuard PID photoionization detector transmitter consists of a UV light source, a detection chamber, a sample draw pump, and associated electronic driver and measurement circuits. The contents of the Lamp Cleaning Kit (part number 081-0002-000) include: lamp cleaner, swabs, finger cots, and lens paper. The contents of the Accessory Kit (part number 033-0912-000) include: sensor puller, Magnet Key, and screwdriver. Prior to factory shipment, the RAEGuard PID is calibrated and tested using isobutylene gas. The calibration of all newly purchased RAE Systems instruments should be tested by exposing the sensor(s) to a known concentration calibration gas before the instrument is put into service for the first time. For maximum safety, the accuracy of the RAEGuard PID should be checked at least monthly when operated in a relatively clean environment. However, in a less clean, highly humid, or variable environment, it may require more frequent (such as once a week) accuracy checks for optimal performance. Recalibrate the unit if readings are outside the limits defined by the user. RAE Systems recommends the following procedure, based on the ISEA (Industrial Safety Equipment Association) protocol, to establish the interval between verification checks: 1. The protocol defines the difference between a functional (bump) test and a full calibration. A functional (bump) test is defined as a means of verifying calibration by using a known concentration of test gas to demonstrate that an instrument’s response to the test gas is within acceptable limits. A full calibration is defined as the adjustment of an instrument’s response to match a desired value compared to a known concentration of test gas as defined in section 2.5 of this manual. 2. During a period of initial use in the intended atmosphere, perform a daily functional (bump) test to ensure there is nothing degrading sensor performance. The period of initial use must be of sufficient duration to ensure that the sensor is exposed to all conditions that might have an adverse effect. 3. Any instrument that fails a functional (bump) test must be adjusted by means of a full calibration procedure before further use. 4. If the tests demonstrate that it is not necessary to make adjustments, then the time interval between checks may be lengthened. For maximum safety, this interval should not exceed 30 days. 4 RAEGuard PID 2.1 Physical Description Physical Dimensions The design of RAEGuard PID allows it to be easily mounted and interfaced with a fixed-point gas monitoring system. The detector transmitter is housed in a 5.0" L x 5.0" W x 4.5" H (127 mm x 127 mm x 115 mm) explosion-proof case with two holes 5.25" (133 mm) apart from center to center. 4.90" [124.46] 3/4" - 14 NPT 3" [127.00] 3/4" - 14 NPT ZERO SPAN OK FAULT LOW HIGH + MODE O 5/16" - O 4 1/2" [114.30] 5 1/4" [133.35] 3/4" - 14 NPT 1.08" [27.43] 4.60" [116.84] RAEGuard PID Standard Version Installation. Sample Gas Flow The RAEGuard PID has an internal diaphragm pump that pulls the sample gas in and forces it out through its outlet. The gas is drawn in through the bottom opening and pushed out through the upper left, while the upper right hole is used for all electrical connections. Outlet Sample Intake RAEGuard PID flow-through intake and output The sample pump runs intermittently according to the programmable duty cycle. The default 40% duty cycle causes the pump to be on for 8 seconds and off for 12 seconds every 20 seconds. www.raesystems.com 5 2.2 Installation and Access Instructions WARNING 1. A minimum of 18 inches (45 cm) of explosion-proof conduit must be used at cable entry in group B atmospheres. CSA requires seals in conduit exceeding 5 feet (1.5 meters) in group C atmospheres. Note: For European applications, the installation must comply with the requirements of EN 60079-14. 2. To prevent ignition of hazardous atmospheres, area must be free of flammable vapors and supply circuit must be disconnected before removing cover. 3. Keep cover tight while circuits are alive. Mounting First, decide where the transmitter will be mounted. (Refer to installation drawing, below.) Drill two holes in the mounting surface, with the centers of the holes spaced 5.25 inches (133 mm) apart. Mount the RAEGuard PID using suitable screws. OK FAULT LOW HIGH + MODE - 5.25" (133 mm) Instrument Assembly Removal Prior to service, make sure power is OFF. Observe all Hazardous Location Safety procedures. 1. Unscrew the housing top from the housing bottom. 6 RAEGuard PID 2. Insert the small cylindrical end (key) of the RAEGuard PID Magnet Key (p/n 033-2032-000) into the hole on the left side of the support post. SIDE VIEW TOP VIEW Key End Magnet End Two views of RAEGuard PID Magnet Key. Support Post Lock Open Magnet Key 3. Turn the Magnet Key 90° counterclockwise to rotate the support post to the “Open” position. You will feel the tension slacken, which indicates you have turned the support post far enough. Support Post Lock Open Magnet Key Caution: Use only the provided Magnet Key to turn the support post. Inserting a longer metal object (such as a screwdriver) may damage the circuit board while rotating the support post. www.raesystems.com 7 4. Carefully lift the entire instrument assembly halfway out of the RAEGuard PID bottom housing. Instrument assembly halfway out of bottom housing with 8-pin connector plugged in Detail of 8-pin electrical connector unplugged 5. Unplug the white 8-pin electrical connector. Use tweezers to disconnect the Tygon® tubing from the effluent (output) side of the pump. 6. Remove the entire instrument assembly from the housing bottom. Electrical Wiring 1. Inside the housing bottom are two green terminal block plugs attached to the terminal block on the circuit board. Unplug the two terminal block plugs from the terminal block. Use tweezers, an IC puller, or needle-nose pliers and lift the terminal blocks straight out. 8 RAEGuard PID Note: The terminal block plugs accept 16 AWG to 28 AWG wire. Use 16 AWG or 18 AWG wire for long wiring runs, which can be up to 1 km (1,000 meters) long 2. Lace the wires through the RAEGuard PID’s wire hole(s) and connect wires to the corresponding pin numbers of the terminal blocks: Wire Alarm Common High Level Alarm Contact Low Level Alarm Contact 4-20 mA Output Power Supply Negative/Output Common Power Supply Positive (9-36VDC) Not Used (troubleshooting only) Not Used (troubleshooting only) Pin Number 1 2 3 6 7 8 4 5 Wire Color Yellow Green Orange Blue Black Red Brown Purple Instrument Assembly Installation 1. Plug both green terminal block plugs back into the correct terminal block headers. Keep extra wires as close to the inside enclosure wall as possible. 2. Plug the white 8-pin connector back into its socket. 3. Carefully place the instrument assembly back into the housing bottom, sliding the hole in the bottom of the assembly over the support post. As you lower the assembly into the housing, make sure the support post passes freely through the hole in the circuit board. Note: Be sure to reconnect the effluent Tygon® tubing before placing the assembly all the way down into the housing. www.raesystems.com 9 4. Gently rock the assembly to ensure that it is properly seated and the hole in the support post is fully visible above the circuit board. 5. Use the RAEGuard PID Magnet Key to rotate the support post 90º clockwise, which secures the instrument assembly in the housing. 6. Tightly screw the housing top to the housing bottom. Caution: Damage to the LCD may result if the housing is screwed down before the assembly is seated all the way down. If you encounter resistance, remove the housing top and check that the instrument assembly is properly seated. 7. Ground the unit using the screw connection to the lower left of the sample inlet in order to reduce the chance of electrical shock. Sample Gas Plumbing Designed as a flow-through unit, the RAEGuard PID is designed to draw a sample from up to 100 feet (30 meters), or against a vacuum of up to 20 inches of water (38mm Hg). The pump can draw up to 40 inches of water, but in this case, the flow will be reduced and the pump may require more frequent maintenance. The typical flow rate without tubing or a vacuum is 550 to 650 cc/min while the pump is on in the 20-second cycle. See RAE Systems Technical Note 140 for details on tubing pressure drop and time delays for extension tubing. If the gas supplied is under pressure, throttle the flow so that it is within the range of 0.6 to 2.0 liters per minute. Any tubing used must be inert to chemical reaction or physical adsorption. We recommend Teflon® or stainless steel tubing with an inner diameter between 1/16" (1.5875 mm) and 3/16" (4.7625 mm). Do not use Tygon® or other soft plastic tubing, as these absorb many organic vapors. Note: Tubing of 1/16" (1.5875 mm) inside diameter may cause excessive pressure drop and should be used only for sampling distances of ≤ 20 feet (6 meters). 10 RAEGuard PID 2.3 Display and Alarm Functions System Initialization When the RAEGuard PID system power is turned on, it initializes and an “InIt” message appears on the display. As the transmitter is warming up, the lamp and pump turn on as each component is checked, and the LEDs blink all at once. The countdown timer appears on the screen for the 6second warm-up. Reading Display As the transmitter enters the Reading Display, it automatically starts testing for errors and goes through a cycle of checking each alarm condition. If there are no errors or alarm conditions, the green “OK” LED is lit and the gas concentration is displayed. If there is an error, the “Fault” LED blinks and an error message blinks on the screen. Each alarm condition has a corresponding LED that blinks an amber color when the readings are outside a specified range or limit. Refer to Section 5: Troubleshooting Tips for alarm relay logic details and Appendix B for Maximum Reading Capabilities and Indications. Alarm Contacts The alarm contacts can be used to drive user-supplied external alarms such as a light or buzzer. The low alarm contact closes when the display reads over the programmed low alarm limit. When the reading exceeds the high alarm limit, the low alarm contact opens and the high alarm contact closes. When the display is over-range, the high alarm contact remains closed and the output jumps to 22 mA to allow remote detection. A fault condition can be detected by a drop to 2 mA output; no dry contact closure occurs. Access to Programming Functions The RAEGuard PID has no external switches, but instead uses the magnetic end of the RAEGuard PID Magnet Key to activate switches built into the unit. To use the RAEGuard PID Magnet Key, briefly touch the glass above the MODE circle or the triangles labeled [+] and [-]. Then remove the key straight out and away from the RAEGuard PID. Access the Calibration menu from the Reading Display by keying [MODE], or access the Advanced menu by keying [+], [-], and then [MODE]. www.raesystems.com 11 2.4 Programming Menu The programming menu lets you change the operating parameters using the magnetic sensing key. To operate the key, briefly tap the display glass directly above the triangles labeled [+] or [-] or the [MODE] circle. Important! Do not drag the key sideways, or two functions may be activated. To access the programming menu from the Reading Display, press [+], [-], and then [MODE] in sequence. Then step through the parameters shown below by keying [MODE]. Each tap of the key on [MODE] advances to the next item in sequence. Note: The RAEGuard PID transmitter returns to the Reading Display after 60 seconds of idle time. Display Message Submenu Parameter FGM-1000 FGM-1001 FGM-1002 Span Gas Value C100 C10.0 C10.00 Correction Factor CF1.0 CF1.0 CF1.0 Low Alarm Limit L200 L20 L5 High Alarm Limit H500 H50 H12 Pump Duty Cycle* P40 P40 P40 * If the Pump Duty Cycle value is changed, the unit should be recalibrated with zero and span calibration gases. Note: Submenus only cycle through once. When [MODE] is keyed after accessing the Pump Duty Cycle submenu, the transmitter returns to the Reading Display. Anytime a submenu screen is idle for more than 15 seconds, the transmitter returns to the Reading Display. To change a value, press [MODE] until the correct parameter appears. To increase a value, press [+]. To decrease a value, press [-]. Press [MODE] when you are finished changing the value. 12 RAEGuard PID If a value has changed, the new value blinks on the LCD. Press [-] to discard changes and advance to the next submenu item. Press [+] to save changes. The “SAUE” message appears on the screen to confirm changes have been saved. 2.5 Calibration Procedures The RAEGuard PID is calibrated using a two-point calibration process. First, use a “zero gas.” Then use a “span gas” containing a known concentration of a standard reference gas, to set the second point of reference. Any gas can be used for calibration, but the greatest accuracy comes from calibrating with the same gas as is being measured. However, if a span gas cylinder of the measured gas is not available, isobutylene (IBE) may be used to calibrate, and a Correction Factor (CF) may be applied. See section 2.6 for Correction Factor procedures.The recommended isobutylene span gas concentration depends on your RAEGuard PID’s range. Below are the default values: RAEGuard PID Range 1000 ppm 100.0 ppm 20.00 ppm Calibration Gas 100 ppm 100 ppm 10 ppm RAEGuard PID Inlet Connect calibration gas cylinder and then turn on gas. RAEGuard PID connected to gas cylinder with calibration adapter. www.raesystems.com 13 WARNING The calibration of all newly purchased RAE Systems instruments should be tested with a known concentration calibration gas before the instrument is first put into service. For maximum safety, the accuracy of the RAEGuard PID should be checked with a known concentration calibration gas. Note: Zero calibration must be performed before span calibration. To perform a calibration, you need a cylinder of zero gas, a cylinder of span gas, and tubing. The gas regulator should provide a flow of at least 600 cc/min. Zero Calibration 1. Connect the zero gas cylinder to the barbed gas inlet port on the RAEGuard PID with tubing. A charcoal tube may be connected to provide zero air. 2. To access the Calibration menu, press [MODE] from the Reading Display. Zero calibration appears first, as indicated by the “ZErO” message on the screen. Optional: To advance to span calibration, press [MODE] a second time. “SPAn” appears on the screen. Skip to the Span Calibration instructions in the next section. Optional: To exit the calibration menu, press [-] to return to the Reading Display. 3. Turn on the gas flow. Press [+] to start calibration. The “Zero” LED starts blinking, and the “ZErO” message alternates with a 60-second countdown timer. Optional: Before countdown reaches zero, you may press any key to interrupt zero calibration in order to advance directly to span calibration. 14 RAEGuard PID 4. Once the countdown reaches zero, the “Zero” LED stops blinking, and the zero calibration data is saved. 5. Turn off the gas flow from the calibration gas cylinder and remove it. Zero calibration automatically advances to span calibration when zero calibration is complete. Span Calibration 1. Connect the span gas cylinder to the RAEGuard PID’s barbed gas inlet port. Optional: To exit the calibration menu altogether, press [-] to return to the Reading Display. Alternatively, after 60 seconds of idle time, it automatically returns to the Reading Display. 2. Once the countdown reaches zero, the “Span” LED stops blinking. 3. If the PID (photoionization detector) sensitivity is acceptable, the span data is calculated and saved. 4. If the PID sensitivity is unacceptable, the screen alternately flashes a “SPAn” and “FAIL” message until any key is pressed. Note: If span failure occurs, it may be necessary to clean or replace the PID lamp. 5. In case of span failure, you may restore the original calibration data by pressing [+] when “rStr” appears on the screen. Then the transmitter returns to Reading Display. Otherwise, press [-] or [MODE] to return to zero calibration to restart the entire calibration process. 6. The calibration procedure is complete. After a few seconds, the RAEGuard PID returns to the Reading Display. 7. Turn off the flow of gas from the calibration gas cylinder and remove it. www.raesystems.com 15 2.6 Correction Factors for Other Gases CAUTION: Calibrating the RAEGuard PID to a specific gas does not make it selective to that gas. A PID is a broadband detector that always responds to all the gases the lamp can ionize, and gives the readout in equivalent units of total VOC for the calibration gas. Correction Factors have been determined that enable a large number of chemicals to be quantified using only a single calibration gas, typically isobutylene (IBE). When the instrument is calibrated with IBE, there is no need to recalibrate it when other compounds are to be measured. Rather, a Correction Factor (CF) can be applied to have the PID readout in units of the new compound. The CF is the ratio of the response to isobutylene over the response to a particular compound. It is defined as: CF = True VOC Concentration PID Reading Once the CF has been established, the true concentration can be obtained by multiplying the reading by the CF: True VOC Concentration = CF x PID Reading For example, if the RAEGuard PID is calibrated to isobutylene and reads 10 ppm on a source of toluene in air (CF = 0.5), then true toluene concentration = 0.5 x 10 ppm = 5.0 ppm. Correction factors are inverse to sensitivity. Compounds with CF greater than 1.0 are less sensitive than isobutylene, and those with CF of less than 1.0 are more sensitive than isobutylene. Appendix A gives a short list of CFs. An extensive list is available in RAE Systems Technical Note 106. 16 RAEGuard PID There are three ways to use these Correction Factors to measure the concentration of another gas: A. Programming the Correction Factor 1. Calibrate the RAEGuard PID using isobutylene gas as described in Section 2.5. 2. Program the Correction Factor for the specific gas as described in Section 2.7. 3. The unit now directly displays the concentration in ppmv (parts per million by volume) of the specific gas. B. Modifying the Span Gas Value 1. When programming the span gas value, multiply the true isobutylene concentration by the CF. Example: Benzene has a correction factor of 0.53 relative to isobutylene gas. Correction Factor x standard value = compensated value Example: 0.53 x 100 ppm = 53 ppm for benzene 2. Enter a span gas value of 53 and calibrate with 100 ppm isobutylene as described in section 2.5. 3. The unit now displays the concentration in ppmv of the specific gas (for example, benzene). C. Manual Conversion 1. Calibrate the RAEGuard PID unit using isobutylene gas as described in Section 2.5. 2. Multiply the reading by the Correction Factor to obtain the true concentration of the specific gas. 2.7 Calibration With Other Compounds Note: Correction Factors introduce some error, and therefore it is always preferable to calibrate directly with the gas to be measured, if available. However, calibrating with compounds that have Correction Factors >1 may cause a calibration “FAIL” error. This is because compounds with low sensitivity generate less of a response signal than the RAEGuard PID expects. In this case, you should modify the span value to a number equal to: (calibration gas concentration) / CF Then program in the CF for measurement. www.raesystems.com 17 For example, to calibrate using a standard of 100 ppm of hexane gas, which has a CF of 4.3, do the following: 1. Program the span gas concentration to: 100 ppm hexane = 23 ppm 4.3 2. Program the CF to 4.3. 3. Zero calibrate. 4. Apply 100 ppm hexane and initiate span calibration. At the end of the calibration countdown, the display should indicate 23 ppm. After exiting to the normal concentration display, the reading should be close to 100 ppm. 2.8 4-20 mA Current Output The current output correlates with the display reading as follows: Display Reading Iout = 4 + (16 x Full Scale Range ) Thus, a display reading of 50 ppm on the 100 ppm model of the RAEGuard PID corresponds to an output of: 50 I = 4 + (16 x 100 ) = 12 mA out A reading of 50 ppm on the 1000 ppm model corresponds to: 50 I = 4 + (16 x 1000 ) = 4.8 mA out When a Correction Factor is programmed, it modifies both the display reading and the current output. For example, if 25 ppm isobutylene is applied to the 100 ppm model with no CF applied (that is, if CF=1.0), the display reads 25 ppm and Iout = 8 mA. If the same gas is applied with a CF of 2.0, the display reads 50 ppm and Iout = 12 mA. Current outputs outside the 4-20 mA range (for example, 0 mA, 2 mA, or 22 mA) indicate failure modes (see Section 5). 18 RAEGuard PID 2.9 Duty Cycle The pump duty cycle can be varied between 30% and 70% of every 20second interval. Thus, a 70% duty cycle means that the pump is on for 14 seconds and off for 6 seconds. During the pump’s off time, the lamp remains on to generate ozone and “burn off” heavy contaminants that may build up on the lamp and sensor. The shortest duty cycle of 30% gives the most lamp self-cleaning and thus the best sensor stability over the long term. The longest duty cycles should be used only where rapid response is crucial to the measurements. It is not currently possible to run the pump continuously (that is, the duty cycle cannot be set to 100%). 3. Theory of Operation The RAEGuard PID uses a discharge UV (ultraviolet) lamp as a high-energy photon source. After sample gas is drawn into the ionization chamber by the pump, light emitted from the UV lamp ionizes a portion of the VOC gas molecules. A pair of electrodes inside the ionization chamber captures the ions and measures the resulting current. Because the measurement is essentially non-destructive, the effluent gas can be used for further analysis if desired. The RAEGuard PID is a microcontroller-based instrument. After the electrical signal from the PID sensor is conditioned and digitized, the microcontroller processes the data and then displays the results locally and reconstructs the digital data into a standard 4-20 mA current signal. The lamp failure detector monitors the UV light source, and the pump current sensor monitors the pump operation. Failure conditions are immediately indicated by LED, a message on the display, and a specified electrical current signal. The instrument has three magnetic sensing keys. Using the RAEGuard PID Magnet Key, it is possible to calibrate the RAEGuard PID and change the alarm level setting via the magnetic front-panel keypad. The instrument is powered by a DC power supply located in a safe area. The power supply on the printed circuit board contains a switching and www.raesystems.com 19 linear regulator that converts the main input voltage to 3.3V and 5V DC to power the entire circuit. Sensor Gas In Pump Gas Out Electrometer A/D Transmitter UV Lamp 4-20 mA Display Lamp Driver Power Supply Microcontroller Keypad Flame-arresting metal frit From Controller 4. Maintenance You should clean the PID sensor and the lamp when one of the following occurs: 1. The reading is inaccurate even after calibration. 2. The reading is very sensitive to air moisture. 3. A chemical liquid has been sucked into the unit and has damaged it. Housing Display Lock hole Support post Pump PID sensor Terminal block Sensor gasket #005 O-ring Gas inlet Housing base Exploded view of RAEGuard PID components. 20 RAEGuard PID 4.1 Cleaning the PID Sensor and Lamp During the course of normal operation, a film of gas vapor may build up inside the PID sensor. The rate of film build-up depends on the type and/ or the concentration of vapors being sampled. Cleaning the sensor helps avoid a drifting response at high humidity. In clean ambient environments, clean the sensor once a year. Refer to Section 5 Troubleshooting Tips for indications that the sensor needs cleaning. PID Sensor If the lamp does not turn on or there is excessive film build-up on the lamp window, the RAEGuard PID produces a failure signal (2 mA) for current output. This indicates the lamp requires cleaning. Periodically clean the lamp window to remove film deposits and restore lamp sensitivity. Exercise care when cleaning the lamp window so that the surface is not damaged. Follow this procedure for cleaning lamps or sensors: 1. Remove the instrument assembly from the housing body. (Refer to Section 2.2, Installation Instructions.) The instrument assembly may also be sent in for repair. Refer to Chapter 5 Troubleshooting Tips. Lamp 2. Loosen the two screws below the sensor, but do not completely remove it. 3. Use the IC puller to remove the sensor. Pull it straight out with a slight rocking motion, using some force, since the sensor will be snug in its place. Do not touch the sensor’s electrode pins. 4. Dip the entire PID sensor into GC Grade methanol. Cleaning the PID sensor in an ultrasound bath for about 15 minutes is highly recommended. Do not disassemble the sensor for cleaning. Note: Never touch the window surface with fingers or anything that might leave behind film or dirt.. 5. Dry the sensor thoroughly. Never touch the electrode pins of the sensor with your hands. 6. Examine the sensor for visible damage such as corrosion, bent pins, or any other mechanical damage. If the sensor is corroded or damaged, contact RAE Systems service for replacement. 7. Carefully examine the sensor O-ring for cracks that may cause a leak. Replace as necessary. 21 www.raesystems.com 8. Carefully pull out the lamp. Avoid contact with the flat window surface. 9. Clean the lamp window surface by wiping it with anhydrous methanol* on a cotton swab. Rub in a circular motion with moderate pressure. * Caution: Water degrades window surfaces. 10. After cleaning, hold the lamp up to the light at an angle to detect any remaining film. Repeat the process until the lamp window is clean. 12. Re-insert the clean lamp, making sure the lamp’s 1/2" Teflon® Oring is in place. 13. Re-insert the clean sensor block. One of the four pins is thicker than the other three to act as a key and ensure proper alignment. 14. Replace the instrument assembly into the housing body (refer to Section 2.2 Installation Instructions). 15. Inspect the large O-ring on the body for damage and replace it if necessary. Then screw on the cover. 4.2 Pump Replacement Follow this procedure for removing the pump: 1. Remove the instrument assembly from the housing body. (Refer to Section 2.2, Installation Instructions.) The instrument assembly may also be sent in for repair. Refer to Chapter 5 Troubleshooting Tips. 2. Disconnect the white 5-conductor connector that connects the pump and the circuit board. 22 RAEGuard PID 3. Disconnect the tube from the left inlet on the pump. A small-blade screwdriver may be helpful in prying the hose off of the connector. Alternatively, you may use an IC puller or needlenose pliers. 4. Hold the pump and remove the two Phillips screws from the base of the instrument assembly. 5. Lift the pump out of the instrument assembly. Replace the pump with a new pump (part number 033-3003-100). Follow this procedure: 1. Slide the pump into place inside the instrument assembly and locate its two screw holes over the matching holes in the instrument assembly’s base. 2. Screw in the two Phillips screws until the pump is held snugly. 3. Reconnect the hose to the left pump inlet. Important: Make sure to reconnect the tube between the effluent (output) port and the right port on the pump. 4. Connect the 5-pin connector of the cable from the pump to the matching connector base on the circuit board. 5. Replace the instrument assembly into the housing body (refer to Section 2.2 Installation Instructions). 6. Inspect the large O-ring on the body for damage and replace it if necessary. Then screw on the cover. 4.3 Filter Adapter The RAEGuard PID must not be operated without a filter in the inlet path. Refer to RAE Systems Technical Note TN-187 for further details. www.raesystems.com 23 5. Troubleshooting Tips Note: Before diagnosing measurement problems, perform zero and span calibration. Symptom Reason Solution Symptom Reason Solution Symptom Reason Solution Symptom Reason Solution Symptom Reason Solution Symptom Reason Solution 24 Reading abnormally high. Dirty sensor block. Excessive moisture. Clean or replace sensor block. Eliminate/control source of moisture and/or temperature difference. “Span Failure” signal. Dirty sensor. Weak/defective lamp. Clean sensor block. Replace sensor block. Replace lamp. Reading abnormally low; reading jumping around randomly. Dirty or weak lamp. Incorrect calibration. Sample tubing restricts flow or absorbs gas. Clean or replace lamp. Recalibrate unit. Use inert or wider-bore tubing. No response during calibration. No standard gas flow. Pump defective or blocked. Low sensitivity to calibration gas. Weak lamp. Make sure standard gas flows into unit. Unblock flow path or replace pump. Use different calibration gas. Replace lamp. Full-scale measurement in humid environment. Dirty or wet sensor. Clean sensor with methanol using an ultrasound bath, and then dry thoroughly. Low 4-20 mA output. Power supply is lower than specified. Check power supply voltage and connection. RAEGuard PID Instrument Failure Table Error & Reason Solution Error & Reason Solution Error & Reason Solution Error & Reason Solution Error & Reason Solution E001 Lamp failure. Change the lamp. E002 Pump failure. Make sure wires are not loose and that there are no mechanical obstructions in the pump motor. Replace pump assembly. E003 Calibration fails. Perform zero and span calibrations. Clean sensor. Clean or change lamp. Check gas flow path. Check calibration gas. E004 Zero drift. Perform zero and span calibration. Electrically ground to housing using screw at lower left of inlet. E005 Gas sensitivity beyond range of instrument. Use different calibration gas and use within measurement range limits. Dilute gas. www.raesystems.com 25 Alarm Relay Logic External Alarm Low Alarm LED LCD Low Reading Exceed High Alarm Limit Over range High Alarm High Reading High Alarm High ADC Saturated (max) Sensor Fault, Lamp Fail Sensor Fault, Pump Fail Sensor Fault, Calibration Fault Sensor Fault, Sensor Drift High Alarm Fault Low Alarm Fault Low Alarm Fault Low Alarm Fault Low Alarm Fault Flashing 8888 Flashing E005 Flashing E001 Flashing E002 Flashing E003 Flashing E004 Exceed Low Alarm Limit Analog Output Based on reading Based on reading 22 mA 2 mA 2 mA 2 mA 2 mA 2 mA Appendix A. Correction Factors The following is a partial list of Correction Factors for a number of commonly used compounds for the PID sensor with 10.6 eV lamp. (Refer to RAE Systems Technical note TN-106 at www.raesystems.com for complete lists of Correction Factors). Table A: Correction Factors for PID with 10.6 eV Lamp Compound Acetylaldehyde Acetic acid Acetone Acrylic acid Allyl alcohol Ammonia 26 Correction Factor 5.5 14 1.1 12 2.4 9.7 RAEGuard PID Table A: Correction Factors for PID with 10.6 eV Lamp Continued Benzene Butadiene Butyl acetate, nButyl acrylate, nCarbon disulfide Cyclohexane Cyclohexanone Dichloroethene, t-1,2Diesel Fuel Diethylamine Dimethylhydrazine, 1,1Epichlorohydrin Ethanol Ethene Ethyl acetate Ethyl acrylate Ethyl benzene Ethyl ether Ethyl hexyl acrylate, 2Ethyl sulfide Gasoline vapors Gasoline, whole Heptane, nHexamethyldisilazane Hexane, nHydrazine Hydrogen sulfide Isobutane Isobutene Isobutyl acrylate 0.53 1.0 2.6 1.6 1.2 1.4 1.0 0.45 0.66 0.97 0.78 10 12 10 4.6 2.4 0.52 1.1 1.1 0.51 0.85 1.0 2.6 0.24 4.3 2.6 4.1 120 1.00 1.5 Table continued on next page www.raesystems.com 27 Table A: Correction Factors for PID with 10.6 eV Lamp Continued Isopropanol Jet fuel JP-4 Jet fuel JP-5 Jet fuel JP-8 Methyl acrylate Methyl ethyl ketone Methyl isobutyl ketone Methyl methacrylate Methyl t-butyl ether Nitric oxide Octane, nPerchoroethene Pinene, aPinene, bPropene Styrene Tetrahydrofuran Toluene Trichloroethene Vinyl chloride Xylene, mXylene, oXylene, p- 6.0 0.99 0.6 0.6 3.7 0.86 1.2 1.4 0.91 5.2 1.8 0.58 0.31 0.37 1.7 0.42 1.8 0.5 0.52 2.0 0.43 0.59 0.45 For more data, see RAE Systems Technical Note TN-106.  The VOC Correction Factors are measured relative to isobutylene gas at <5% relative humidity and 25º C, typically at 50 ppm to 100 ppm concentrations. The Correction Factors may change at higher concentrations or different temperature and humidity conditions. The Correction Factors should be multiplied by the instrument reading to obtain the actual concentration of the gas. If the correction factor of a gas is <1.0, then the sensitivity to the gas is higher than that of isobutylene. 28 RAEGuard PID www.raesystems.com 29 Range Saturation Analog Output for Value Over Range 20.62 ppm 4 mA - 20.0 mA 20.5 mA 22 mA Flashing 8888 Flashing 8888 22 mA 22 mA 1031 ppm 4 mA - 20.0 mA 20.5 mA FGM-1000 0.0 ppm - 1000 ppm Over Range Display Flashing 8888 103.1 ppm 4 mA - 20.0 mA 20.5 mA Saturation Analog Output Value FGM-1001 0.1 ppm - 100 ppm FGM-1002 0.0 ppm - 20.0 ppm Model Appendix B. Maximum Reading Capabilities and Indications Appendix C. Limited Product Warranty RAE Systems (RAE) warrants the RAE products to the original owner purchased directly from RAE or an authorized RAE Reseller to be free of defects in workmanship for a period of one year from the date of original shipment to owner exclusive of consumables, including batteries, filters, and calibration gases. Pumps and 10.6 eV electrodeless discharge lamps are warranted for one year. RAE’s obligation under this warranty is limited to replacing or repairing, at RAE’s option, any defective part if returned to a RAE authorized factory repair center, with shipping charges prepaid by the buyer, and which, upon inspection by RAE, shall prove to have been defective in normal use and service. To maintain warranty, Purchaser must perform maintenance and calibration as prescribed in the Operation and Maintenance manual. In the event of defect, Purchaser will notify RAE designated factory repair center in advance, and if trouble diagnosis procedures are unable to determine and remedy the condition, a Return Material Authorization (RMA) will be issued to assure proper repair and logistics tracking. Warranty does not extend to any equipment malfunction or damage which results from alteration, accident, theft, misuse, abuse, abnormal use, improper or unauthorized repairs, or improper maintenance. RAE neither assumes nor authorizes any other firm or person to assume on RAE’s behalf any liability in any way connected with the sale of RAE products. This express warranty shall extend to the buyer of record only and not to sales made by the buyer’s customers. Except for the warranty of title, the foregoing express warranty is in lieu of any and all other warranties, whether expressed or implied, including the implied warranties of fitness for a particular purpose and merchantability. Seller’s liability under the warranty provided herein exclusive of insurance process shall be limited to a refund of purchase price. 30 RAEGuard PID Appendix D. RAE Systems Contacts RAE Systems by Honeywell World Headquarters 3775 N. First St. San Jose, CA 95134-1708 USA Phone: 408.952.8200 Fax: 408.952.8480 E-mail: [email protected] Web Site: www.raesystems.com RAE Systems Technical Support Monday through Friday, 7:00AM to 5:00PM Pacific Time +1.888.723.4800 (toll-free) email: [email protected] RAE Systems Europe ApS Kristinehøj 23 A DK-2770 Kastrup Denmark Phone: +45 86 52 51 55, From 8.00 - 17.00 Fax: +45 86 52 51 77 RAE Systems (Hong Kong) Ltd. Room 8, 6/F, Hong Leong Plaza 33 Lok Yip Road Fanling, N.T. HONG KONG Phone: +852.2669.0828 Fax: +852.2669.0803 www.raesystems.com 31 RAE Systems by Honeywell World Headquarters 3775 N. First St. San Jose, CA 95134-1708 USA Phone: 408-952-8200 Fax: 408-952-8480 E-mail: [email protected] p/n 033-4001-001 Rev B, January 2009 www.raesystems.com