The Michell Instruments WM291 Relative Humidity & Temperature Transmitter includes the interchangeable Hygrosmart module. The interchangeable
module lets you recalibrate the transmitter simply by replacing the sensor head with the Hygrosmart module. As a result, maintenance
costs are greatly reduced and down-time is minimized.
The WM291 has a relative humidity range 0 to 100% with an accuracy of less than ±2% RH (5-95% RH). The temperature range is
-30 to 70°C (-22 to 158°F) with an accuracy of ±0.4°C (±0.72°F). The WM291 has metric or US measurement units selectable through
software.