Infrared thermometers have become essential tools in various industries, from healthcare and food safety to manufacturing and HVAC systems. Their ability to measure temperature without physical contact makes them ideal for fast, hygienic, and convenient monitoring. However, like all measuring instruments, infrared thermometers calibration to maintain accuracy and reliability.
In this article, we’ll explore the importance of calibrating infrared thermometers, how the calibration process works, industry standards, and tips for maintaining optimal performance.
What is Infrared Thermometer Calibration?
Calibration is the process of comparing the measurements of a device to a known standard or reference, and then adjusting it (if necessary) to align with the standard. In the case of infrared thermometers, calibration involves comparing the device’s temperature readings with those of a calibrated blackbody source—a device that emits known, controlled infrared radiation.
Infrared thermometers rely on detecting infrared radiation emitted by an object’s surface and converting that radiation into a temperature reading. Over time and usage, the accuracy of these devices may drift due to factors such as environmental exposure, aging of components, or handling issues.
Calibration ensures that the thermometer continues to provide precise and trustworthy readings—an essential requirement in critical applications.
Why Calibration is Important
1. Accuracy in Critical Applications
In healthcare settings, even a small error in body temperature measurement can lead to incorrect diagnoses. Similarly, in food safety or industrial processes, temperature discrepancies can result in compliance failures or unsafe conditions.
2. Compliance with Standards
Many industries must comply with national and international standards such as ISO 9001, FDA, or HACCP. Calibrated instruments are often a regulatory requirement for audits and certifications.
3. Quality Assurance
Regular calibration ensures consistent product quality. For manufacturers, an inaccurate thermometer could compromise entire production batches.
4. Reliability Over Time
Even high-quality instruments can drift over time. Routine calibration checks help detect these changes early, reducing the risk of unexpected failures or incorrect readings.
How Infrared Thermometer Calibration is Performed
Calibration of an infrared thermometer typically involves the following steps:
1. Use of a Blackbody Calibrator
A blackbody calibrator is a specially designed device that emits uniform and known levels of infrared radiation at a controlled temperature. It serves as a reference for the calibration process.
2. Setup and Alignment
The infrared thermometer is positioned at a specified distance and angle from the blackbody target. Proper alignment is crucial for accurate calibration.
3. Stabilization
The blackbody is allowed to reach a stable temperature. Depending on the range of calibration, multiple temperatures may be tested (e.g., 35°C, 50°C, 100°C).
4. Measurement and Comparison
The infrared thermometer takes readings of the blackbody’s temperature. These readings are compared to the known values, and any deviations are noted.
5. Adjustment
If the thermometer has internal calibration settings, adjustments are made to correct the discrepancies. If not, a calibration certificate is issued indicating the deviations.
Calibration Standards and Guidelines
Calibration processes should follow industry standards and guidelines such as:
- ISO/IEC 17025 – General requirements for the competence of testing and calibration laboratories.
- NIST (National Institute of Standards and Technology) – Provides traceable temperature standards for calibration.
- ASTM E1965 – Standard specification for infrared thermometers used for human body temperature measurements.
Accredited calibration labs follow these standards to ensure high accuracy and traceability.
How Often Should You Calibrate an Infrared Thermometer?
The frequency of calibration depends on the use-case and the criticality of the application. As a general guideline:
- High-risk or regulated environments (e.g., medical, food industry): Calibrate every 6–12 months.
- Industrial or manufacturing settings: Calibrate annually or more often if the device is used frequently.
- After any significant impact or environmental exposure: Calibrate immediately to confirm no damage has occurred.
Many manufacturers also recommend a calibration schedule in the user manual.
Signs Your Thermometer Needs Calibration
- Readings are consistently off or vary widely between uses.
- The thermometer has been dropped or exposed to extreme conditions.
- It shows large deviations compared to other calibrated devices.
- Routine checks show inconsistencies.
Choosing a Calibration Service Provider
When selecting a calibration service provider, consider the following:
- ISO/IEC 17025 accreditation – Ensures the lab follows globally recognized calibration standards.
- Traceability to national/international standards – Ensures results are valid and recognized.
- Turnaround time – Especially critical for industries relying on continuous operations.
- Calibration certificate – Should detail the results, standards used, date, and next due date.
Some providers also offer on-site calibration for large-scale industrial operations.
Maintaining Infrared Thermometer Accuracy Between Calibrations
- Avoid direct exposure to sunlight or heat sources when not in use.
- Store in a clean, dry place with the protective cap on.
- Do not drop or mishandle the device.
- Regularly clean the lens as dirt or smudges can affect readings.
- Perform quick checks against known temperature sources to detect drifts.
Conclusion
Calibrating your infrared thermometer calibration is not just a technical requirement—it’s a critical part of maintaining precision, safety, and quality in any professional setting. Whether used in hospitals, kitchens, laboratories, or industrial sites, these devices must perform with high accuracy. Regular calibration ensures compliance with standards, supports operational efficiency, and builds trust in your measurements.