Scarlet TWL-1S Heat Stress Detector

Category Tag
The TWL-1S is used to monitor and assess thermal risk level indoor and outdoor. It has a smart user-friendly interface which allow users to instantly identify the thermal risk level result based on different colors. Users can also do data logging directly by connecting the device to windows PC via the USB cable. Wireless pager for remote alerting system is available for the TWL-1SR model.


  • Wet Bulb Globe Temperature (WBGT)
  • Thermal Work Limit (TWL)
  • Globe Temperature
  • Dry Bulb Temperature
  • Relative Humidity
  • Wet Bulb Temperature
  • Wind Speed

Data Sheet

Item Description
Air Temperature Range 0…60 °C / Accuracy ±0.6 °C
Globe Bulb Indoor Range 0…80 °C / Accuracy ±1.0 °C (15…40 °C); ±1.5 °C (others)
Globe Bulb Outdoor Range 0…80 °C / Accuracy ±1.5 °C (15…40 °C); ±2.0 °C (others)
Relative Humidity Range 5…95 %rh / Accuracy ±3% (at 25 °C; 10…90 %rh) ±5% (others)
Wind Speed Range 0.5…10 m/s / Accuracy ±(2% of reading + 0.2) m/s
Dimensions Body 59 x 37 x 316 mm (w x d x h). Wind cup (top view) diameter 182 mm
Operating range electronics -10…60 °C
Accuracy at 23 ±5 °C ±1.0 %rh / ±0.2 K
Power supply / consumption 4 AAA 3V battery, power supply 6 mA consumption without lighting
Probe protection Polypropylene plastic cage
Measurement interval 2 seconds
Data logger Yes. Min data rate 1 min up to 60 min, 2,000 data.
Connection Interface Mini USB (UART)
Calibration / adjustment Scarlet calibration kit
Wireless Connection (Optional) 433 MHz (TWL-1SR Model)