My new pressure sensor system is giving unexpected readings. How can I determine if the problem is with the voltage output pressure sensor or my data acquisition (DAQ) system?
A systematic troubleshooting approach is the most effective way to isolate the source of error in an instrumentation loop. By separating the sensor from the rest of the system, you can determine if the fault lies with the measurement device or the signal processing hardware. Here is a step-by-step diagnostic guide based on industry best practices.
Featured voltage output pressure sensor products
DPS Low Differential Pressure Transmitter - Ultra low differential pressure transmitter for HVAC applications with 4-20mA current loop or amplified voltage output signal in pressure ranges from 0.1 mb up to 1 bar differential. 
Monitoring data center positive pressure with a low-range differential transducer - Low-range differential pressure transducer for verifying and monitoring critical positive air pressure between a data center equipment room and adjacent areas, ensuring compliance with required ≥5 Pa and ≥10 Pa thresholds.
Verify System Basics:
- Power Supply: Ensure the voltage supplied to the sensor is within its specified operating range.
- Wiring: Double-check that the electrical connections are correct.
Isolate and Test the Sensor:
- Disconnect the sensor’s signal wire from your DAQ, PLC, or display.
- Using a calibrated digital voltmeter (DVM), measure the voltage directly across the sensor’s signal output. This provides a direct, unfiltered reading of the sensor’s output.
Perform a Bench Test with a Calibrated Source:
- Connect the sensor to a known, stable pressure source, such as a pressure calibrator or deadweight tester. This allows you to apply precise pressures and validate the sensor’s response.
- Create a data table, recording the sensor’s direct voltage output (from your DVM) at several pressure points across the measurement range (e.g., 0%, 25%, 50%, 75%, and 100% of full scale).
Featured pressure calibration products
140 bar / 2,000 psi Hand Operated Air Pressure Test Pump – ADT919A - Generate air pressure up to 140 bar / 2,000 psi one handed.
DM01-500-HD High Range Digital Pressure Gauge - The DM01-500 HD high range pressure gauge is available in pressure ranges from 0 to 600, 1000, 1600, 2000 & 2200 bar.
Compare Measured Data to Specifications:
- Calculate the ideal output for each pressure point.
- Factor in the sensor’s allowable tolerances. This includes the accuracy, and the specified zero & span offset range.
- If your DVM readings fall within the calculated range of ideal output plus/minus the combined tolerances, the sensor is performing correctly.
Investigate the Data Acquisition System:
- If the bench test confirms the sensor is healthy, the problem lies downstream in your signal processing chain.
- Input Range: Confirm your DAQ card or PLC analogue input is configured for the correct voltage range.
- Software Scaling: Check the scaling factors used in your software or PLC logic to convert the voltage reading back into a pressure value (e.g., bar, psi). Incorrect scaling is a very common source of error.
By following this process, you can confidently determine whether the issue originates from the voltage output pressure sensor or the instrumentation used to read it.
Featured voltage output pressure sensor products
DMD331 Compact Differential Liquid Pressure Sensor - Wet wet differential pressure sensor with a high overpressure rating on both positive and negative pressure side for protection against damage.
Low Cost Miniature Pressure Transducer – ASL - The ASL low cost miniature pressure transmitter, has a piezoresistive ceramic pressure sensor which is chemically inert and has very fast dynamic response.
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Related Technical Terms
- 4 Wire
- Cardinal Points
- Isolation Diaphragm
- Primary Pressure Reference Standard
- Secondary Pressure Standard
- Stainless Steel Pressure Sensors
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