Pyrometer gauges are precision instruments used to measure high temperatures, especially in applications like exhaust gas temperature (EGT) or cylinder head temperature (CHT) monitoring. While most pyrometer systems (especially digital ones) come pre-calibrated, it's important to understand when calibration may be necessary and how it works.
Do Pyrometer Gauges Need Calibration?
- Analog pyrometers: Typically do not require calibration in the field. If readings seem inaccurate, the issue could be related to the sensor or wiring or possibly the gauge itself.
- Digital pyrometers: These are usually calibrated at the factory. Some advanced models offer field-adjustable calibration settings, but most do not require frequent recalibration unless used in extreme or critical applications.
What Calibration Actually Refers To
Pyrometer calibration usually means verifying and adjusting the measuring electronics (the gauge) to correctly interpret the voltage signal coming from the thermocouple sensor (usually Type K or J). This is not the same as calibrating the thermocouple itself.
If calibration is needed, it is generally the instrument (gauge/display) that is adjusted—not the sensor.
How to Check Calibration
Before attempting calibration, follow these steps:
- Verify Sensor Condition
Make sure your thermocouple sensor is in good condition—check for damage, corrosion, or incorrect wiring.
- Use a Known Temperature Source
Place the thermocouple in a known temperature environment, such as:
- A precision dry block calibrator
- A certified reference thermometer
- Boiling water (~ 100°C / 212°F at sea level)
- Ice bath (~ 0°C / 32°F)
- A precision dry block calibrator
- Compare Readings
If your gauge shows a temperature significantly different from the known source, calibration may be necessary.
How to Calibrate (If Your Gauge Supports It)
If your pyrometer gauge has a calibration function, the process may involve:
- Accessing a calibration mode using buttons or a dial (refer to your product manual)
- Applying a known temperature to the sensor
- Using the interface to match the displayed temperature to the known value
- Saving the adjustment
Note: Most standard automotive and industrial gauges do not include user calibration options. If yours doesn't, and you believe it's out of spec, the unit may need to be serviced or replaced.
What If My Gauge Can’t Be Calibrated?
If calibration is not supported and readings are inaccurate:
- Inspect the thermocouple sensor and extension wire
- Check polarity and wire type – ensure you're using proper Type K or J extension wire
- Replace the gauge if it’s no longer reading consistently
Summary
- Most pyrometer gauges are factory-calibrated and require no adjustment
- Calibration is typically performed on the display unit—not the sensor
- Use a known temperature source to verify gauge accuracy
- If your gauge supports field calibration, follow the manufacturer’s instructions
- For persistent issues, inspect or replace the sensor, wiring, or gauge
Still have questions about pyrometer calibration or sensor compatibility?
Contact our technical support team – we’re here to help you maintain accurate and reliable temperature monitoring.