| Question |
Answer |
| How does IR temperature measurement work? |
Infrared temperature measurement works by detecting the thermal radiation that all objects above absolute zero naturally emit. An optical system collects this radiation from the target, filters it to a specific wavelength band, and focuses it onto a detector that converts the radiation intensity into an electrical signal. Using Planck's radiation law and the target's emissivity, the instrument calculates temperature—all without physically touching the object. Land has refined this technology over 75+ years for industrial accuracy. |
| What is the principle of a pyrometer? |
A pyrometer operates on the principle that hotter objects emit more intense thermal radiation at shorter wavelengths. By measuring the intensity of infrared radiation at a specific wavelength (or wavelength ratio) and applying calibration based on Planck's law, the instrument derives the target temperature. The key advantage is non-contact measurement from a safe distance—essential for hot, moving, hazardous or electrically live targets common in steel, glass, cement and power generation industries. |
| What's the difference between contact and non-contact measurement? |
Contact methods (thermocouples, RTDs) require physical attachment to the target and measure the sensor temperature, which must equilibrate with the target—introducing response lag and potential errors from heat conduction. Non-contact pyrometers measure directly from a distance, respond instantly (typically milliseconds) and don't affect the target. Non-contact is preferred for moving targets, inaccessible locations, very high temperatures, food/pharmaceutical hygiene requirements or when contact would disturb the process. |
| Can you measure molten metal without contact? |
Absolutely—non-contact measurement of molten metal is a core Land application. The SPOT+ MM (Meltmaster) pyrometer is specifically engineered for liquid metal from approximately 700°C to 1,700°C, using a carefully selected wavelength that minimizes emissivity variations. For portable spot-checks, the Cyclops 390L handheld pyrometer measures molten metal up to 3,000°C with traceable accuracy. Both are trusted in primary steelmaking, foundries, aluminum casting and specialty metals processing. |
| What is the typical pyrometer accuracy? |
Typical pyrometer accuracy from Land instruments is ±0.5% of reading or ±1°C, whichever is greater—for example, ±5°C at 1,000°C. This assumes correct emissivity setting, proper optical alignment and a clean sight path. The Cyclops L series achieves reference-grade accuracy of ±0.5% + 1°C, which is why it's used to verify and calibrate fixed sensors. For process control applications, this accuracy level supports tight temperature tolerances that translate directly to product quality and yield improvements. |