How to Check the Accuracy of Your Infrared Thermal Camera at Home (Two-Point Temperature Verification Guide)

Accurate temperature measurement is critical when using an infrared thermal camera for electrical inspection, HVAC diagnostics, building analysis, or industrial maintenance. Even minor temperature deviations can lead to incorrect conclusions about overheating components, insulation failure, or energy loss.

While full calibration should always be performed by certified laboratories, you can perform a simple two-point thermal accuracy check at home using freezing and boiling water. This method verifies whether your thermal camera readings fall within an acceptable tolerance range.

Below is a step-by-step guide to checking your thermal camera accuracy safely and effectively.

Why Emissivity Matters in Infrared Thermography

Before starting, it’s important to understand emissivity. Shiny metal surfaces reflect infrared radiation, which can cause false temperature readings. To avoid this, we use black electrical tape, which has a known emissivity of approximately 0.95.

Preparation Steps

1. Apply a vertical strip of black electrical tape to a clean, dry aluminum can.

2. Turn on your infrared camera.

3. Set emissivity (ϵ) to 0.95.

4. Measure temperature only on the taped surface — not the bare metal.

This ensures you are reading true surface temperature rather than reflected ambient heat.

Cold Point Verification (0°C / 32°F)

The freezing point of water provides a stable, reliable reference temperature.

Steps:

• Fill the can with crushed ice.

• Add a small amount of cold water to create an ice-water slush.

• Wait 2–3 minutes for stabilization.

• Aim your thermal camera at the center of the tape strip.

Expected Result:

The camera should read approximately 0°C (32°F).

Take three measurements. If the deviation exceeds ±2°C, further calibration may be required.

Hot Point Verification (100°C / 212°F)

Boiling water provides your second reference point.

⚠️ Note: Boiling point decreases with elevation (approximately 0.5°C per 1,000 feet).

Steps:

• Empty and dry the can completely.

• Carefully fill it with boiling water.

• Wait one minute for the tape to reach temperature.

• Avoid steam interference.

• Aim at the taped surface.

Expected Result:

The reading should be close to 100°C (212°F) at sea level.

Again, record three measurements and check for deviations greater than ±2°C.

Best Practices for Accurate Thermal Camera Accuracy Check

✔ Stay 2–3 feet away to avoid body heat reflection.

✔ Tilt the camera slightly (5–10° off perpendicular).

✔ Observe the difference between tape and shiny metal — tape shows true temperature.

Why This Thermal Check Is Important

Performing this two-point accuracy check:

• Builds confidence before critical inspections

• Detects early sensor drift

• Reinforces proper emissivity use

• Improves professional thermography practice

While not a replacement for certified calibration, this thermal camera accuracy check method helps ensure your infrared camera remains reliable in real-world applications.

Reliable data leads to better decisions. And better decisions protect equipment, safety, and uptime.