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The Extech RH25 is a pocket-sized Heat Index Psychrometer Pen designed to monitor heat stress conditions during hot, humid days. Its pen-style form factor and 1.8 oz weight allow it to fit easily into a pocket, making it convenient to carry for spot measurements wherever needed.
Per the datasheet, the RH25 is intended to help prevent heat stroke during outdoor activities, sporting events, and indoor workplace environments. The instrument supports six measurement and calculation modes — Relative Humidity, Heat Index, Temperature, Dew Point, Wet Bulb, and Wet Bulb Globe Temperature (WBGT) — covering the parameters most relevant to assessing heat-related risk.
ValueTronics stocks, inspects, and ships test and measurement instruments from a 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois. Equipment is verified by our in-house technicians before shipment — not drop-shipped from a third party — which lets us stand behind every unit we sell and respond directly when questions arise.
| Specifications | Range | Resolution | Basic Accuracy |
|---|---|---|---|
| Temperature | -4 to 122°F (-20 to 50°C) | 0.1°F/C | ±1°F/0.6°C |
| Relative Humidity | 0 to 99.9%RH | 0.1%RH | ±3%RH |
| Wet Bulb | -4 to 122°F (-20 to 50°C) | 0.1°F/°C | |
| Dew Point | -108.4 to 122°F (-78 to 50°C) | 0.1°F/°C | |
| Heat Index | -50.8 to 401°F (-46 to 205°C) | 0.1°F/°C | |
| WBGT | -13 to 130°F (-25 to 54.5°C) | 0.1°F/°C | |
| Dimensions | 5.5x1.4x0.7" (140x35x18mm) | ||
| Weight | 1.8oz (50g) |
Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.
Model No
Extech
Condition
New
Manufacturer
Extech
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