RT8A infrared thermometer measures the temperature of moving materials, webs or inaccessible objects without contact in hostile production environments. Four models cover operating temperatures from 0-500° C to 1,000° F. The NEMA 4X/IP65 rated housing can be supplemented by optional cooling and lens purging facilities when required to provide two levels of protection. A choice of mounting and protection accessories makes it easy to install at the optimum point in the process. No tools are required to access the protected thermometer. Accurate, reliable and stable temperature measurement is assured by the thermometer's response time, which is adjustable from 1-10s; accuracy within <0.5% of span; and minimal drift with change in ambient temperature of £1.5° C per 10° C.