A Silicon Diode Circuit for Direct Measurement of the WBGT Thermal Stress Index

A simple instrument is described for the assessment of a thermal environment by continuous monitoring and computation of the Wet-Bulb Globe Thermometer (WBGT) heat stress index. Silicon diodes are used as the temperature transducers. A simple resistive network for weighted summation of the voltages has been developed. The instrument is battery-operated and suitable for laboratory and field work. Monitoring and recording is possible from a remote site.