Instructions

2RH25enGB_v1.15/15
Introduction
ThankyouforselectingtheExtechInstrumentsModelRH25HeatIndexPsychrometer.TheRH25
measuresTemperatureandRelativeHumidity(usingprecisioncapacitanceRHsensor).TheRH25
alsocalculatesanddisplaysHeatIndex,DewPoint,WetBulb,andWetBulbGlobetemperatures.
TheHighTemperatureAlarmfeaturealertstheuserwhenHeat
Indexor WetBulbGlobelevels
exceeduserpresetlimits.
DataHoldandMIN/MAX/AVGmemoryutilitiesmakeiteasiertorecallimportantdata.
This device is shipped fully tested and calibrated and, with proper use, will provide years of
reliableservice.Pleasevisitourwebsite(www.extech.com)tocheckforthe
latestversionofthis
UserGuide,ProductUpdates,andCustomerSupport.

Description
Meter
1. Sensorarea
2. Displayarea(LCD)
3. POWERbutton
4. HOLDbutton
5. MODEbutton
6. Batterycompartmentonrearofinstrument
Display
TEMP Temperature
RH RelativeHumidity
HI HeatIndex
DP DewPointtemperature
WB WetBulbtemperature
WB/HIWetBulbGlobetemperature
MAX Maximumreadingmemory
MIN Minimumreadingmemory
AVG Averagereadingmemory
HOLD DataHold(freezesdisplay)
BAT LowBatterysymbol
% PercentunitsforRHreadings
o Degreessymbol
fortemperatureunits
E UsedtodisplaytemperatureunitsCorF