Focus on sensor calibration

A sensor or instrument may need to undergo a series of changes known as sensor calibration in order for the instrument to operate as correctly and error-free as feasible. The benefits of calibrating include some of the following.

What is sensor calibration?

Sensors and measuring systems, among other measurement tools, are calibrated to check their accuracy and repeatability. Calibrated sensors are necessary for precise, consistent, and repeatable measurement outputs. Calibration is one of the crucial conditions for effective quality assurance.

In the field of measurement technology, sensor calibration refers to the processes used to establish, under specific circumstances, the relationship between the values of a measuring output by a measurement instrument—such as a sensor or measuring system—and the corresponding values of a measuring instrument established with standards.

Working principle of sensor calibration

• A sensor or group of sensors needs to be calibrated in order for an instrument to perform as accurately or error-free as is practical.
• Sensors are components of electronics. They are aware of changes occurring at work. Unwanted output values are produced when the operating environment of the sensors is abruptly and unintentionally changed.
• As a result, there is a discrepancy between the observed and expected output. Comparing the measured output to the anticipated output is the process of calibrating a sensor.
• Calibration is necessary to enhance the functioning of the sensor. It is used to estimate structural defects caused by sensors.
• The difference between the sensor's projected value and its measured value is known as the structural error.

Why is sensor calibration so important

Even the most sensitive and exacting measurement system or equipment can lose accuracy due to usage, aging, and environmental factors. Therefore, it needs to be recalibrated frequently. According to DIN EN ISO 9001, a method for test equipment monitoring should be implemented, and measurement devices need to be calibrated. Because of this, many businesses have quality assurance programs that call for calibration on a regular basis.

How often should we calibrate?

Any instrument's calibration schedule should be determined by the application. To preserve confidence in the traceability chain, re-calibrations must be done at the proper intervals. The interval's duration will vary depending on a variety of factors, including the significance of the measurements, the stability of the instrument, the frequency and method of usage, the level of required uncertainty, etc. The user must consequently decide when to recalibrate. Only you are aware of the results' significance or, alternatively, the financial, production, or safety implications of a systematic density inaccuracy.

Application of Sensor Calibration

1. The simplest definition of sensor calibration is the comparison of the desired output and the measured output. These errors may be caused by a variety of circumstances. Incorrect zero-reference errors and mechanical damage errors, etc. are a few examples of defects in sensors. Calibration and adjustment are two different concepts.

2. Once an adjustment is performed to remove the error, the error is adjusted to the necessary amount.

Calibration uses sensor model simulations. Sensor calibration is used in control systems to monitor and alter the control processes. Automatic systems calibrate its sensor to acquire precise results.

3. Depending on the measurement, multiple calibration techniques are used for sensors. For the calibration of pressure sensors, force sensors, and torque sensors, several calibration procedures and devices are employed.

Errors in sensor measurement

1. Incorrect Zero Reference Error: The instrument may not have a correct zero reference. Modern sensors and transmitters are electronic equipment, and the reference voltage or signal may drift over time due to changes in environmental parameters like temperature, pressure, or time.

2. Error from Sensor Range Shift: The "sensor's range" may change as a result of the previously mentioned circumstances, or perhaps the process's operating range has changed. For instance, a process may currently operate in the 0 to 200 pounds per square inch (PSI) range, but changes to its operation will require it to operate in the 0 to 500 PSI range (PSI).

3. Error caused by mechanical wear or damage: Sensor measurement errors may be caused by mechanical wear or damage. This kind of mistake typically necessitates the equipment being repaired or replaced.

Conclusion

A sensor, or set of sensors, must be calibrated in order for an instrument to perform as accurately or error-free as is practical. The calibration procedure is used to improve the system's operation and performance. It aids in lowering systemic mistakes. An accurate reading from a calibrated sensor can be used as a benchmark for comparison. One sensor's undetected inaccuracy could lead to systemic degradation. To ensure that automated systems operate accurately, it is crucial to calibrate the sensor.