The wavelength range and response time of the two-color infrared thermometer
Wavelength range of dual color infrared thermometer
The emissivity and surface properties of the target material determine the spectral response or wavelength of the thermometer. For high reflectivity alloy materials, there is a low or varying emissivity. In high-temperature areas, the optimal wavelength for measuring metal materials is near-infrared, which can be selected as 0.18-1.0 μ m wavelength. Other temperature zones can use wavelengths of 1.6 μ m, 2.2 μ m, and 3.9 μ m. Due to some materials being transparent at certain wavelengths, infrared energy can penetrate these materials, and special wavelengths should be selected for these materials. If measuring the internal temperature of glass, wavelengths of 10 μ m, 2.2 μ m, and 3.9 μ m (the measured glass should be very thick, otherwise it will pass through) should be selected; Measure the internal temperature of the glass using a wavelength of 5.0 μ m; It is advisable to use a wavelength of 8-14 μ m for measuring low areas; For example, when measuring polyethylene plastic film, a wavelength of 3.43 μ m is used, while for polyacetylates, a wavelength of 4.3 μ m or 7.9 μ m is used. Select wavelengths of 8-14 μ m for thicknesses exceeding 0.4mm; For example, CO2 in the flame is measured using a narrowband wavelength of 4.24-4.3 μ m, C0 in the flame is measured using a narrowband wavelength of 4.64 μ m, and N02 in the flame is measured using a narrowband wavelength of 4.47 μ m.
Response time of dual color infrared thermometer
The response time represents the reaction speed of an infrared thermometer to changes in the measured temperature, defined as the time required to reach 95% of the energy required to reach the final reading (5% energy is required for dual color colorimetric fibers). It is related to the time constants of the photodetector, signal processing circuit, and display system. The response time of the new infrared thermometer can reach 1ms. This is much faster than contact temperature measurement methods. If the target is moving at a fast speed or when measuring rapidly heated targets, a fast response infrared thermometer should be selected, otherwise it will not achieve sufficient signal response and will reduce measurement accuracy. However, not all applications require fast response infrared thermometers. When there is thermal inertia in a stationary or target thermal process, the response time of the thermometer can be relaxed. Therefore, the selection of response time for infrared thermometers should be adapted to the situation of the target being measured.
