Brooks 5850I Manual - [EBook]

Brooks 5850I Manual - [EBook]

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Brooks 5850I Manual - [EBook]By continuing to use our site, you agree to our use of cookies. For further information, please see our Privacy Policy. Find a model number or product name Ultra-high purity products for the semiconductor industry Actively in use for decades in thousands of applications worldwide, they utilize a unique, extremely stable flow sensor to provide the reliable, accurate and repeatable measurement and control that today’s demanding industrial manufacturing processes require. Flow RangeFlow RangeFlow RangeFlow RangeFlow Range. Brooks Instrument designs, manufactures and tests its products to meet many national and international standards. Because these instruments are sophisticated technical products, you must properly install, use and maintain them to ensure they continue to operate within their normal specifications. Every day, flow customers all over the world turn to Brooks Instrument for solutions to their gas and liquid low-flow applications. This instruction manual is intended to provide the user with all the information necessary to install, operate and maintain the Brooks 5850i Mass Flow Controller. Repeatability 0.25 of rate Response Time Less than 6 seconds to within 2 of full scale final value with a 0 to 100 command step. Command Input Jumper Selectable: 0-5 Vdc, Input resistance 200k ohm or 4-20 mAdc, Input resistance 75 ohm. Leak Integrity 1 x 10-9 Atm. If the packing case is damaged, the local carrier should be notified at once regarding his liability. A report should be submitted to the Product Service Department, Brooks Instrument, Hatfield, Pennsylvania 19440-0903. This can be obtained at Brooks Instrument, Product Service Department, 407 West Vine Street, Hatfield, PA 19440-0903, or call toll free 1-888-554-FLOW (3569). Pin 2 indicates the flowrate with a 0-5 Vdc signal proportional to the mass flow rate. Disconnect the power to the mass flow controller and any cables to the D-connector and the valve coil connector.http://latiendasegura.com/contable_prueba/userfiles/a-first-aid-kit-manual.xml

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This circuit provides a slow injection of the gas as a protection to the process, particularly those using a volatile or reactive gas. Full gas flow is achieved in approximately 20 seconds. The setpoint should still be set at 100 flow (5.000V). Measure the flow rate using suitable volumetric calibration equipment. If an in-line filter is used, the filtering element should periodically be replaced or ultrasonically cleaned. 4-2 Troubleshooting A. System Checks The 5850i is generally used as a component in gas handling systems which can be quite complex. Anticipate potentiometer out of adjustment. Adjust anticipate potentiometer. Refer to Section 3-5. Output stays at zero regardless of setpoint and there is no flow through the controller. The sensor assembly may be removed or replaced by referring to Section 4-4, Disassembly and Assembly. If the sensor assembly is cleaned and reinstalled, a calibration check should be performed. Remove the two screws securing the bracket (24) and PC Board (15). Remove the bracket and PC Board. 11.Remove the two screws (18) and washers (19) securing the sensor assembly (16). Remove the sensor assembly. If the air gap is too small, the plunger travel may be insufficient to fully open the valve. Also, the magnetic force may be too high for a given valve coil voltage. If the air gap is too large, the magnetic force will be insufficient to raise the plunger and the valve will not open. This is due to the difference in heat capacities between the two gases. If this point is between two orifice sizes, select the next largest size orifice to ensure adequate flow. If the orifice selected falls below.0013, choose.0013 size orifice. For this example the.007 size orifice would be selected. 4-7 Restrictor Sizing The restrictor assembly is a ranging device for the sensor portion of the controller. Hatfield, PA 19440 U.S.A. Emne: Till?g til instruktions manual. Reference: CE m?rkning af Masse Flow udstyr Dato: Januar-1996. Hatfield, PA 19440 U.S.A.http://www.masimo.nl/upload/a-first-course-in-complex-analysis-solutions-manual.xml Subject: Addendum to the Instruction Manual. Reference: CE certification of Mass Flow Equipment Date: January-1996. Hatfield, PA 19440 U.S.A. Sujet: Annexe au Manuel d’Instructions. Reference: Certification CE des Debitmetres Massiques a Effet Thermique. Date: Janvier 1996. Hatfield, PA 19440 U.S.A. Oggetto: Addendum al manuale di istruzioni. Riferimento: Certificazione CE dei misuratori termici di portata in massa Data: Gennaio 1996. Erityista huomiota on kuitenkin kiinnitettava signaalikaapelin valintaan. It eliminates the need for continuous monitoring and readjustment of gas pressures to provide a stable gas flow. We know there are plenty of differences when it comes to used equipment and quite often, choosing between different pieces is difficult, especially when the equipment is not sitting right in front of you. Well, what if you were able to see a piece of equipment before you purchased it. Not just a picture from the manufacturer's website, but the actual piece of equipment you would receive. You can zoom in close to see the labels with the serial number or zoom out to see the overall condition of the equipment. It's like having the store come to you. InstraView Request Form To get started. 1. Fill in the request form below 2. We'll send you an email letting you know exactly when your piece of equipment will be available for viewing Item to Inspect: 77273-8 - Brooks Instrument 5850i Air Mass Flow Controller Error Please contact us to complete your request. Thank You! We will be contacting you shortly. The following instructions must be adhered to and integrated into your safety program when installing, using and maintaining Brooks Products. Read all instructions prior to installing, operating and servicing the product. If this instruction manual is not the correct manual, please see back cover for local sales office contact information. Save this instruction manual for future reference.https://labroclub.ru/blog/dcx2496-service-manual If you do not understand any of the instructions, contact your Brooks Instrument representative for clarification. Follow all warnings, cautions and instructions marked on and supplied with the product. Inform and educate your personnel in the proper installation, operation and maintenance of the product. Install your equipment as specified in the installation instructions of the appropriate instruction manual and per applicable local and national codes. Connect all products to the proper electrical and pressure sources. To ensure proper performance, use qualified personnel to install, operate, update, program and maintain the product. When replacement parts are required, ensure that qualified people use replacement parts specified by Brooks Instrument. Unauthorized parts and procedures can affect the product's performance and place the safe operation of your process at risk. Look-alike substitutions may result in fire, electrical hazards or improper operation. Ensure that all equipment doors are closed and protective covers are in place, except when maintenance is being performed by qualified persons, to prevent electrical shock and personal injury. The Directive is applicable within the European Economic Area (EU plus Norway, Iceland and Liechtenstein). Pressure equipment can be traded freely within this area once the PED has been complied with. Section 1 of this manual contains important safety and operating instructions related to the PED directive. ESD (Electrostatic Discharge) Handling Procedure: 1. Power to unit must be removed. 2. Personnel must be grounded, via a wrist strap or other safe, suitable means before any printed circuit card or other internal device is installed, removed or adjusted. 3. Printed circuit cards must be transported in a conductive container. Boards must not be removed from protective enclosure until immediately before installation.https://difumarket.com/images/cannon-c60dhkf-manual.pdf Removed boards must immediately be placed in protective container for transport, storage or return to factory. Comments This instrument is not unique in its content of ESD (electrostatic discharge) sensitive components. Most modern electronic designs contain components that utilize metal oxide technology (NMOS, SMOS, etc.). Experience has proven that even small amounts of static electricity can damage or destroy these devices. Damaged components, even though they appear to function properly, exhibit early failure. 3 Installation and Operation Manual Dear Customer, We appreciate this opportunity to service your flow measurement and control requirements with a Brooks Instrument device. Brooks provides an array of flow measurement and control products for various industries from biopharmaceuticals, oil and gas, fuel cell research and chemicals, to medical devices, analytical instrumentation, semiconductor manufacturing, and more. The Brooks product you have just received is of the highest quality available, offering superior performance, reliability and value to the user. It is designed with the ever changing process conditions, accuracy requirements and hostile process environments in mind to provide you with a lifetime of dependable service. We recommend that you read this manual in its entirety.https://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1634727f788f88---dae4p-manual.pdf Should you require any additional information concerning Brooks products and services, please contact your local Brooks Sales and Service Office listed on the back cover of this manual or visit Yours sincerely, Brooks Instrument 4 Installation and Operation Manual THIS PAGE WAS INTENTIONALLY LEFT BLANK 5 Installation and Operation Manual X -TMF-5850i-MFC-eng Section 1 Introduction Paragraph Number Contents Page Number 1-1 Purpose Description Specifications Section 2 Installation Section 3 Operation Section 4 Maintenance Section 5 Parts List 2-1 Receipt of Equipment Recommended Storage Practice Return Shipment Gas Connections Installation In-Line Filter Electrical Interfacing Configuring the PC Board Theory of Operation Operating Procedure Zero Adjustment Calibration Procedure Response General Troubleshooting Sensor Tube Disassembly and Assembly Use of the Conversion Tables Use of Orifice Sizing Nomograph Restrictor Sizing General Section A CE Certification CE Certification of Mass Flow Equipment. This manual is organized into five sections: Section 1 Section 2 Section 3 Section 4 Section 5 Introduction Installation Operation Maintenance Parts List It is recommended that this manual be read in its entirety before attempting to operate or repair the Model 5850i. 1-2 Description The Brooks Model 5850i Mass Flow Controller is used widely in the Semiconductor Industry as well as many others, where manual, electronic or computer controlled gas handling occurs. The Model 5850i consists of three basic units: a flow sensor, a control valve and an integral electronic control system. This combination produces a stable gas flow, which eliminates the need to continuously monitor and readjust gas pressures. Refer to Figure 1-1. Soft Start provides a flow ramping function which slows down the introduction of the process gas for those processes which cannot tolerate rapid flow transition. Refer to Section 2-7 and Figure 1-2.www.digitekprinting.com/bbaexchange/webroot/admin_upload/files/Digilogic-Ddvdc-1-User-Manual.pdf Valve Override permits the user to fully open and close the control valve independent of the setpoint (command) setting. Refer to Section 2-6. Setpoint (Command) permits the user to program the mass flow controller with an external 0-5 Vdc or 4-20 madc signal. Refer to Section 2-6. Low Command Valve Inhibit (Auto Shutoff) prevents the valve from opening whenever the setpoint is less than 2 of full scale. Removable Cleanable Sensor permits the user to clean or replace the sensor. Higher differential pressures are allowable depending on gas and range. Consult factory for details. Output Signal 0-5 Vdc into 2,000 ohms or greater. Maximum ripple 3 mv. Jumper selectable 4-20 madc or 0-20 madc. Command Input Jumper Selectable: 0-5 Vdc, Input resistance 200k ohm or 4-20 madc, Input resistance 75 ohm. Refer to Figure 2-1. Electrical Connections D-type, 15-pin connector (DA-15P). The mass flow controller can be calibrated to other reference standard conditions. Specify at time of ordering. 1-4 11 Installation and Operation Manual Section 2 Installation 2-1 Receipt of Equipment When the equipment is received, the outside packing case should be checked for damage incurred during shipment. A report should be submitted to the Product Service Department, Brooks Instrument, Hatfield, Pennsylvania Remove the envelope containing the packing list. Carefully remove the equipment from the packing case. Make sure spare parts are not discarded with the packing materials. Inspect for damaged or missing parts. Upon removal from storage, a visual inspection should be conducted to verify its condi-tion is as received. This can be obtained at Brooks Instrument, Product Service Department, 407 West Vine Street, Hatfield, PA, or call toll free FLOW (3569). Prior to installation, make certain all piping is clean and free of obstructions. Make no connection on customer end. If positive shut-off is required, it is recommended that a separate shut-off valve be installed in-line.https://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1634728181f826---daedong-tractor-service-manual.pdf 2-6 In-Line Filter It is recommended that an in-line filter be installed upstream from the controller to prevent the possibility of any foreign material entering the flow sensor or control valve. The filtering element should be replaced periodically or ultrasonically cleaned. 2-4 Table 2-1 Recommended Filter Size Maximum Flow Rate Recommended Filter Size 100 sccm 1 micron 500 sccm 2 microns 1 to 5 slpm 7 microns 10 to 30 slpm 15 microns 15 Installation and Operation Manual Section 2 Installation Figure 2-3 Maximum Allowable Loop Resistance 2-7 Electrical Interfacing To insure proper operation, the 5850i must be connected per Figures 2-2, 2-3 and 2-4 and configured according to Section 2-7. As a minimum, the following connections must be made for new installations: Function Chassis Ground Signal Output Return Voltage or Current Signal Output Vdc Supply Supply Common Voltage or Current Setpoint Input Setpoint Return Electrical Hook-up Setpoint (Command) Input The 5850i Mass Flow Controller can be used with a current (4-20 madc) or voltage (0-5 Vdc) setpoint. Reference Brook s device specifications for the setpoint input impedance.) 2-5 16 Section 2 Installation Installation and Operation Manual Signal Output The flow signal output can be measured as a voltage and a current simultaneously on two different pins of the D-connector. Pin 4 indicates the flowrate with either a 0-20 madc or 4-20 madc current signal as determined by jumpers on the pc board (refer to Section 2-7 for jumper positions). The output signal is driven by the MFC into the customer load. Isolating pin 12 (no connection) returns the controller to normal operation. NOTE: For normal operation, pin 12 must be left open (floating). Remove the three screws at the base of the can and remove the top jack post of the D-connector. Remove the can. The can must be replaced before returning the unit to service. Refer to Section 2-6 for the proper electrical hook-up.https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/163472875bb95a---daelim-besbi-service-manual.pdf Refer to Figure 3-5 for pc board jumper locations and functions. Setpoint (Command) Input The mass flow controller can be configured for voltage or current setpoint (command) input. Jumper J7 (green) must be in the right-hand position for 0-5 Vdc setpoint and in the left-hand position for a 4-20 madc setpoint input. Signal Output A 0-5 Vdc flow signal output is always available. The current signal output is jumper selectable for either 0-20 madc or 4-20 madc. Jumpers J3 and J4 (blue) must be in the upper position for 0-20 madc output and in the lower position for 4-20 madc output. NOTE: Both J3 and J4 must be in the same position. Jumpers J3 and J4 do not affect the voltage output. 2-8 Soft Start To enable soft start, place Jumper J2 (red) in the right-hand position (SS). To disable soft start, place jumper J2 in the left-hand position (N). 19 Installation and Operation Manual Section 3 Operation 3-1 Theory of Operation The thermal mass flow sensing technique used in the 5850i works as follows: A precision power supply provides a constant power heat input (P) at the heater which is located at the midpoint of the sensor tube. (Refer to Figure 3-1) At zero or no flow conditions, the heat reaching each temperature sensor (one upstream and one downstream of the heater) is equal. Therefore, the temperatures T1 and T2 are equal. When gas flows through the tube, the upstream sensor is cooled and the downstream sensor is heated, producing a temperature difference. The temperature difference T2-T1 is directly proportional to the gas mass flow. The flow restrictor shown in Figure 3-1 performs a ranging function similar to a shunt resistor in an electrical ammeter. The restrictor provides a pressure drop that is linear with flow rate. The ratio of the restrictor flow to the sensor tube flow remains constant over the range of the meter. Different restrictors have different pressure drops and produce controllers with different full scale flow rates.dienlanhhaiphong247.com/upload/files/Digital-Camera-With-Manual-Exposure.pdf The span adjustment in the electronics affects the fine adjustment of the controller's full scale flow. In addition to the mass flow sensor, the Model 5850i Mass Flow Controller has an integral control valve and control circuit, as shown in Figure 3-2. The control circuit senses any difference between setpoint and the flow sensor signal and adjusts the current in the modulating solenoid valve to increase or decrease the flow. The Model 5850i has the following features incorporated in the integral control circuit: Fast Response adjusted by the anticipate potentiometer. This circuit, when properly adjusted, allows the high frequency information contained in the sensor signal to be amplified to provide a faster responding flow signal for remote indication and use by the control valve. 3-1 20 Section 3 Operation Installation and Operation Manual Figure 3-1 Flow Sensor Operational Diagram Soft Start enabled by moving a jumper on the PC Board. Refer to Section 2-7. Precision 5 Volt Reference allows the direct connection of a setpoint potentiometer to produce a 0-5 Volt command signal to the controller. A precision ten-turn 2k ohm potentiometer with an integral turns counter is recommended. This will permit repeatable adjustments of setpoint to 1 part in 1,000. Valve Override allows full opening and closing of the control valve independent of the command setting. (Refer to Section 2-6) 3-2 Operating Procedure 3-2 a. Apply power to the controller and allow approximately 45 minutes for the instrument to warm up and stabilize its temperature. b. Turn on the gas supply. c. Command 0 flow and observe the controller s output signal. This is primarily caused by changes in temperature between our calibration laboratory and the final installation. The zero flow reading can also be affected, to a small degree, by changes in line pressure and mounting attitude. To check zero, always mount the controller in its final configuration and allow a minimum of twenty minutes for the temperature of the controller and its environment to stabilize. Using a suitable voltmeter or current meter, check the controller output signal. If it differs from the factory setting, adjust it by removing the lower pot hole plug which is located closest to the controller body. Adjust the zero potentiometer (refer to Figure 3-6) until the desired output signal is obtained. NOTE: If the 0-20 ma output is used, adjust zero by monitoring the voltage output signal. This is required because the current output cannot go negative. 3-3 22 Section 3 Operation Installation and Operation Manual 3-4 Calibration Procedure NOTE 1: If the valve has been disassembled and any of the following parts have been replaced, the control valve adjusting procedure in Section 4-4c must be performed before the Model 5850i is calibrated.It is recommended that the calibration be performed only by trained and qualified service personnel. NOTE 3: If the mass flow controller is to be used on a gas other than the calibration gas, apply the appropriate sensor conversion factor. Size the orifice for actual operating conditions (refer to Section 4-5). a. With the controller installed in an unpressurized gas line, apply power and allow approximately 45 minutes for warm-up. During the warmup, adjustment and calibration check procedures, do not allow the control valve to open when gas flow is not present. This situation is not a normal operating mode; it will cause the control valve to abnormally heat up. A meter with an abnormally warm valve will be difficult to calibrate. This situation can be prevented by the valve override closed when there is no gas flow, or setting the setpoint to less than 1. Also avoid unnecessary periods with the valve override open. b. Adjust the anticipate potentiometer fully clockwise (twenty turns). Then adjust the anticipate potentiometer ten turns counterclockwise to center the potentiometer. This will provide a rough adjustment of this circuit and make the flow more stable for calibration. c. Connect the DVM positive lead to the 0-5V signal output (pin 2) and the negative lead to signal common (TP4). If the zero does not repeat, check for leakage. NOTE: Controllers supplied with all-metal valve seats do not provide tight shut-off. A 0-8 leak-through is typical. For metal seat controllers, close a downstream shut-off valve and observe the zero signal. e. Adjust the setpoint for 100 flow (5.000V or 20 madc). Connect the DVM positive lead to TP2 (linearity voltage) and the negative lead to TP4 (signal common). Adjust the linearity potentiometer for an output of 0.0V (zero volts). 3-4 23 Installation and Operation Manual Section 3 Operation f. Connect the DVM positive lead to TP1 (100x sensor voltage) and the negative lead to TP4 (circuit common). To adjust the controller to the proper full scale flow, calculate a new TP1 voltage using the following equation: Adjust the span potentiometer until the voltage at TP1 is equal to the value calculated above. Recheck the flow rate after the flow is stable (at least two minutes). Repeat this check and adjustment procedure until the measured flow rate is within 1 of the desired flow rate. NOTE: The voltage at TP1 is 100 times the output voltage of the sensor. This voltage can range from 1.2 to 12 volts, however, it is recommended that this voltage stays between 2.0 and 9.0 volts for proper operation. If one of the limits is reached, check the orifice and restrictor sizing procedures. Refer to Sections 4-6 and 4-7 respectively. g. Adjust the setpoint for 0 flow. Connect the DVM positive lead to 0-5V signal output (Pin 2) and the negative lead to TP4. If one of the limits is reached, check the restrictor sizing. Refer to Section Response Fast Response Adjustment Two methods of adjusting the step response of the 5850i mass flow controllers can be used. Method Number 1 describes a procedure that will get the step response close to optimum quickly and without any flow measuring equipment. This method should be used when the response time of the flow controller is not critical to overall system performance. Method Number 2 describes a procedure that will allow adjustment of your 5850i mass flow controller to optimum step response performance. This method is the preferred way to adjust the step response. Adjustment of the fast response circuit will not affect the accuracy of the flow controller as adjusted in Section Fast response adjustment (six seconds response specification not guaranteed) NOTE: This procedure requires an oscilloscope, chart recorder or a DVM with a sample speed of three samples per second or greater to monitor the rate of change of the output signal. 3-8 a. Adjust the setpoint for 100 flow and wait about 45 seconds for the flow output signal to stabilize. b. Step the command signal to 0 or activate valve override closed to stop the flow. Observe the flow signal output as it decays. c. The behavior of the flow signal during this transition between 100 27 Installation and Operation Manual Section 3 Operation Figure 3-6 Fast Response Adjustment and 0 flow indicates the adjustment required of the anticipate potentiometer. Refer to Figure If the flow signal measured on pin 2 decays to to -0.5V, then rises to 0V, the anticipate potentiometer is properly adjusted. 2. If the flow signal decays rapidly and goes below -0.5V before rising to 0 V, the anticipate potentiometer must be adjusted clockwise and steps a and b repeated. 3. If the flow signal decays slowly and does not go below V, the anticipate potentiometer must be adjusted counterclockwise and steps a and b repeated. 2. Fast response adjustment (six second response specification guaranteed) Adjustment of the anticipate potentiometer to obtain a flow rate performance to be within 2 of flow rate commanded in less than six seconds after setpoint change requires the use of a fast response flowmeter (500 millisecond response to be within 0.2 of final value or better) in series with the 5850i and a storage oscilloscope or recorder. a. Allow the flow controller to stabilize at 0 setpoint for at least thirty seconds. Make a step in setpoint to the controller from 0-100 of full scale flow and record the output signal of the fast response flowmeter. b. If this signal shows more than 4 overshoot, adjust the anticipate potentiometer one-half to one turn counterclockwise. If the signal does not show overshoot but is not within 2 full scale of final value after six seconds, adjust the anticipate potentiometer one-half to one turn clockwise. Set command potentiometer for 0 of flow. c. Repeat steps a and b until the fast response flowmeter output signal meets the specified response requirements. NOTE: With the equipment on the previous page (3-9), the anticipate potentiometer can be adjusted to give optimum response characteristics for any process. 3-9 28 Section 3 Operation Installation and Operation Manual THIS PAGE WAS INTENTIONALLY LEFT BLANK 3-10 29 Installation and Operation Manual Section 4 Maintenance 4-1 General No routine maintenance is required on the Model 5850i other than an occasional cleaning. This can make the task of isolating a malfunction in the system a difficult one. An incorrectly diagnosed malfunction can cause many hours of unnecessary downtime. If possible, make the following system checks before removing a suspected defective mass flow controller for bench troubleshooting or return, especially if the system is new: 1. Verify low resistance power supply connections and that the correct power supply voltage and signals are reaching and leaving the controller. Apply power, set the setpoint to zero and allow the controller to warm up for 45 minutes. Do not connect to a gas source at this time. Observe the output signal and, if necessary, perform the zero adjustment procedure (Section 3-3). Refer to Section 3-5. more than 5 full scale. Output stays at zero regardless Clogged Sensor. Refer to Section 4-4. Clean sensor. Refer to cleaning. of setpoint and there is no flow through the controller. Clogged Control Valve. Check TP3 with the setpoint at 100. If the voltage is greater than 11V, disassemble and repair the control valve. Refer to Sections 4-4c and Valve override input is grounded. Check valve override input (Pin 12) Defective PC Board. Check the valve override terminal. (Pin 12) Defective PC Board. Replace PC Board. Refer to Section 4-4. Output signal follows setpoint Leaky control valve. Disassemble and repair valve. Refer to Section 4-4C.Output signal follows setpoint Insufficient inlet pressure or pressure drop.Partially clogged sensor. Check calibration. Refer to Section 3-4. Partially clogged valve. Disassemble and repair control valve. Refer to Section 4-4. Valve out of adjustment. Adjust valve. Refer to Section 4-4. Valve guide spring failure. Controller oscillates (see below). Controller grossly out of calibration. Partially clogged sensor. Clean sensor, refer to the cleaning procedure. Flow is higher than desired. Partially clogged restrictor. Replace restrictor. Refer to Section 4-4. Flow is lower than desired. Controller oscillates. Pressure drop or inlet pressure excessive. Adjust pressures. Oversized orifice. Check orifice size. Refer to Section 4-6. Valve out of adjustment. Adjust valve. Refer to Section 4-4. Anticipate potentiometer out of adjustment. Refer to Section 3-5. Faulty pressure regulator. Check regulator output. Defective PC Board. Replace PC Board. Refer to Section 4-4. the output signal will not zero properly, refer to the sensor troubleshooting section and check the sensor.