GT

Globe Temperature (GT)

The Globe Temperature (GT) sensor measures the temperature of the environment in a way that mimics how humans and animals perceive heat. GT absorbs heat from radiation such as the sun, air, and convection. 

A GT sensor with the WBGT calculation helps indicate how hot it feels to a human body by considering air temperature, humidity, and direct sunlight or other radiation sources for an assessment of heat stress levels.

While Heat Index is commonly used by the general public, WBGT is a better indicator for heat stress in the sun.  Heat index is calculated from temperature in the shade and relative humidity.  WBGT also uses the temperature and humidity in its calculation, but temperatures are measured in direct sunshine using the GT. According, the GT sensor is used in conjunction with other sensors to calculate the “Wet Bulb Globe Temperature” (WBGT) heat stress index.

OSHA and many others also use the WBGT as a guide to managing workload in direct sunlight, as do athletic departments (college and high school) and events. Application that benefits from predicting heat stress:

• Sports / athletes
• Workplace safety
• military personnel
• Extreme heat forecast
• Outdoor recreation
• Livestock management
• Crop growth
• Climate change research

The Globe Temperature sensor consists of black-coated, hollow cooper sphere (the globe) that absorbs heat from various sources including radiation. The black coating helps to absorb heat effectively.   This sphere is designed for harsh outdoor conditions.

Inside the GT-1 is a digital temperature sensor for Modbus communication protocol and the GT-2 incorporates an analog thermistor sensor.