Inexpensive, Non Contact Thermometer Sensor offers Narrow Field Of View

To expand on its automotive proven family of intelligent infrared, non contact thermometers, Melexis introduces the MLX90614xAC with narrow Field Of View (FOV). Currently shipping versions of the MLX90614 non contact temperature sensor have a wide Field Of View of 90 degrees and target air conditioning and room heater applications. The MLX90614xAC now being introduced has a Field Of View of only 35 degrees. Design engineers can now measure smaller objects or increase the sensor-object distance with this thermometer. The 35 degree FOV was chosen as the minimal Field Of View achievable without the use of costly infrared optics, while still achieving the excellent accuracy specifications of the original MLX90614.

In detail:
The 35 degree Field Of View of the MLX90614xAC is obtained by adding a viewing angle limiting metal tube to the standard TO-39 housing of the MLX90614. By performing the calibration of the thermometer after this tube has been attached, the accuracy of the temperature measurements can be maintained.

Luc Buydens, Marketing Manager of infrared sensor products at Melexis, comments: “This new addition to our line of low cost, infrared thermometers builds further on the positive feedback we received after the introduction of our integrated infrared sensor, MLX90614. The 35degree Field Of View of this new version of the infrared thermometer enables many new applications like microwave ovens, true non contact fever temperature measurement and industrial temperature control.”

How it works
The sensing element in the MLX90614 is a silicon chip with a thin, micro-machined membrane sensitive to the infrared radiation of a distant object. A custom signal conditioning chip amplifies and digitizes the signal from the membrane and calculates the object temperature using factory set calibration. The digital output temperature is fully linearized and compensated for ambient temperature variations.

The MLX90614xAC applies advanced low noise amplifiers, a 17-bit ADC, and powerful DSP unit in its signal conditioning chip allowing a wide operating temperature range of -40°C to 125°C and an extended object temperature range of -70°C to 380°C while maintaining a temperature resolution of 0.02°C. The MLX90614xAC has a high absolute accuracy of ±0.5°C in the object temperature range of 0°C to 50°C and ±1°C outside that range.