How do you calibrate and maintain pressure sensors in harsh environments?

1 Calibration methods

Calibration is the process of comparing the output of a pressure sensor to a known standard, such as a reference gauge or a deadweight tester. This ensures that the sensor is within its specified accuracy range and can detect any drift, offset, or non-linearity. Various methods of calibrating pressure sensors exist, depending on the type, range, and application of the sensor. Zero calibration involves setting the sensor output to zero when there is no pressure applied. This can correct any offset or bias errors due to environmental factors or sensor aging. Span calibration requires applying a known pressure to the sensor and adjusting the output to match the expected value. This can correct any gain or scale errors due to sensor sensitivity or range. Finally, multi-point calibration involves applying several known pressures to the sensor and recording the output at each point. This can correct any non-linearity or hysteresis errors due to sensor response or repeatability.

2 Maintenance tips

Maintenance is an essential process for inspecting, cleaning, repairing, and replacing pressure sensors to ensure they are performing optimally and durably. This can help prevent sensor failures, malfunctions, or inaccuracies that can compromise safety, quality, or efficiency. To ensure proper maintenance, it is important to follow the manufacturer's recommendations for calibration and maintenance frequency and method. Additionally, use the appropriate tools, materials, and procedures to avoid damaging the sensor or its components. Furthermore, protect the sensor from physical, chemical, thermal, or electrical hazards that can cause corrosion, abrasion, deformation, or short-circuiting. It is also important to check the sensor for any signs of wear, tear, leakage, or contamination and replace it if necessary. Lastly, store and transport the sensor in a suitable container and environment to avoid exposure to dust, moisture, or shock.

3 Environmental challenges

Environmental challenges are external factors that can affect the performance and lifespan of pressure sensors, varying depending on the application and location. Temperature extremes can cause thermal expansion, contraction, or stress, resulting in drift, offset, or non-linearity errors. High humidity or condensation can cause moisture ingress, corrosion, or short-circuiting, resulting in noise, instability, or failure of the sensor output. Mechanical vibration or shock can cause physical damage, deformation, or displacement of the sensor or its components, leading to non-linearity, hysteresis, or dead zone errors. High or low pressure can cause overloading, underloading, or fatigue in the sensor or its diaphragm, causing span, zero, or sensitivity errors.

4 Environmental solutions

Environmental solutions are design features, techniques, or accessories that can reduce the effects of environmental challenges on pressure sensors. These solutions can enhance the accuracy, reliability, and lifespan of pressure sensors in harsh environments. Temperature compensation, for example, involves using a temperature sensor or a mathematical algorithm to adjust the output of the pressure sensor according to the ambient temperature. This can reduce or eliminate thermal errors or drifts. Sealing and coating involves using a protective layer or a barrier to prevent moisture, dust, or chemicals from entering the sensor or its connections. Isolation and damping involves using a buffer or a cushion to absorb or reduce the impact of vibration or shock on the sensor or its components. Lastly, ranging and filtering involves using a suitable pressure range and a signal filter to match the application and the environment of the sensor. These environmental solutions can help prevent overloading, underloading, noise, corrosion, contamination, short-circuiting, damage, deformation, and displacement.

5 Testing and verification

Testing and verification are essential processes for evaluating the performance and quality of pressure sensors in harsh environments. Through laboratory testing, the accuracy, stability, linearity, repeatability, and response of the sensor output or signal can be measured. Field testing is an additional step that involves installing and operating the sensor in its actual application and environment to assess functionality, reliability, durability, and compatibility with the system or device. Certification and validation are also necessary to verify and document that the sensor complies with relevant regulations, codes, or guidelines for the application and environment, thus demonstrating its safety, quality, or efficiency.

6 Here’s what else to consider

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