Extech RHM15 Mini Hygro-Thermometer Monitor
The Extech RHM15 is a compact, pocketable hygrometer/thermometer that continuously monitors and displays relative humidity and air temperature. It also records maximum/minimum values, and includes a clear function to reset those extremes. Its small form factor, tilt stand, and low power consumption make it ideal for use in enclosures, instrument cases, greenhouses, display cabinets, or anywhere environmental monitoring is needed.
Description
The RHM15 is engineered for simple and effective environmental monitoring in both enclosed and open spaces. It features simultaneous display of relative humidity and temperature on a dual-segment LCD — one side shows humidity [% RH], and the other shows temperature (in °F or °C). Internally, it tracks the maximum and minimum readings over time and allows users to reset those values via a CLEAR button. The device operates over a humidity range of 10 % to 99 % RH and a temperature range of 14 to 140 °F (or equivalently –10 to 60 °C). It’s accurate to about ±5 % RH for humidity (in the mid-range) and ±2 °F (≈ ±1 °C) for temperature within the normal operating bounds. The RHM15 is powered by a small LR44 (or AG13) button battery, and includes an auto shutoff and low battery indicator. Its structure is slim and lightweight, with dimensions around 2 x 1.5 x 0.63 inches (51 x 38 x 16 mm) and just 0.8 oz (≈ 24 g) in weight. A built-in tilt stand allows the unit to be propped upright for better readability. It’s especially useful in compact environments like instrument cases, humidors, display cabinets, greenhouses, or anywhere where monitoring moisture and temperature is important.
Features
- Simultaneous display of humidity and temperature
- Range: 10 % to 99 % RH; 14 to 140 °F (≈ –10 to 60 °C)
- Max/Min memory — records highest and lowest values since last reset
- CLEAR function — resets the stored max/min readings
- Compact size and low weight — about 51 x 38 x 16 mm, ~24 g
- Built-in tilt stand — for tabletop or shelf display
- Low battery indicator — alerts when battery is weak
- Battery powered — uses one LR44 (or AG13) cell
- Reasonable accuracy — ±5 % RH (mid-range), ±2 °F for temperature
- Auto shutoff — helps conserve battery life
Includes
- Tilt Stand (built-in)
LR44 Battery
