The Measurement Shop's Guide to Heat Stress Meters

Heat stress meters are important tools for so many industries all over the world. They ensure that environments remain safe for people to work in and provide valuable information on temperature, humidity, wind levels and more. In this blog, The Measurement Shop is going to look at these incredibly useful instruments and provide you with all the information you’ll ever need on the humble heat stress meter.

To read our product focus on the Reed SW700 Heat Stress Stopwatch, please click here.

What is a heat stress meter?

A heat stress meter (also known as a heat stress monitor) is a small handheld device that can be used to measure air temperature, airflow, humidity and direct sunlight. They are used to monitor the heat exposure in a given environment - often a workplace or sports facility – to ensure that the environment is safe for the desired operation. For higher temperature environments, they can also give crucial information on the amount of time that someone should be exposed to more extreme levels of heat. These devices combine a range of different environmental factors which can give a more accurate representation of ‘how hot it feels’ rather than the actual temperature.

Why is heat stress dangerous?

Illnesses related to heat stress can be serious and can result in serious harm or even death in extreme circumstances. Common conditions that can come as a result of heat stress are heatstroke, cramps, heat rashes, headaches, and low blood pressure to name just a few. It must also be considered that many of these symptoms and conditions may not be related to heat exposure, meaning a heat stress related condition is not always easy to spot.

Heat stress can also make pre-existing medical conditions such as cardiovascular and respiratory illness worse, and cases of infertility in both men and women have been known.

Who uses a heat stress meter?

As you can imagine, heat stress measurement is essential in a vast number of different environments, workplaces and industries. Here are some of the most common:

• Restaurants and kitchens
• Factories
• Sports facilities such as gyms, schools and athletic training facilities
• Agricultural environments
• Construction sites
• Mining environments

Any environment in which an individual is exposed to extreme heats, high levels of humidity, lack of proper ventilation or direct sunlight for large periods of time should consider using a heat stress meter. You should also take into account the amount of physical exertion that is required from an individual, as more movement will cause the body to heat up faster.

How does a heat stress monitor work?

Heat stress meters use a number of different sensors that take various environmental measurements to ultimately calculate something known as the WBGT (Wet Bulb Globe Temperature). This is essentially an equation that is used to indicate heat stress levels which takes into consideration different environmental factors, including temperature, humidity and the solar radiation.

The dry bulb temperature represents the ambient air temperature, whilst the wet bulb temperature represents the humidity of the air. Finally, there is the large black globe which measures the globe temperature, or the estimated solar radiation temperature. The WBGT is then calculated using the following equation.

For indoor environments which do not receive any solar radiation, the following equation is used instead:

The Measurement Shop’s range of heat stress meters

Reed R6200 WBGT Heat Stress Meter

The R6200 WBGT from Reed Instruments is a versatile device that measures air temperature, humidity and radiant sunlight with WBGT. This device is easy to use and is commonly used in sports environments, such as gyms and athletic events. Feature a completely user customisable alarm which will sound when a set limit has been reached. Also measures heat index, dew point and barometric pressure. If you require any help on how to operate your R6200, please see the relevant instruction manual from Reed instruments.

Reed SD-2010 SD Series WBGT Heat Stress Meter, Datalogger

The SD-2010 SD Series is currently the second heat stress meter from Reed Instruments that is stocked by The Measurement Shop. This device measures WBGT similarly to the R6200 but can also be used as a real time data logger. Data can be stored on an external SD card where it can be can be saved as an Excel spread sheet without the need for external software. Data can also be tracked live using software that comes with the device. This can be incredibly useful if you need to monitor the temperature levels continuously. If you require any help on how to operate your SD-2021, please see the relevant instruction manual from Reed instruments.

For any help with our range of heat stress meters, please call us on 01908972660.