Introduction; Meter Description; Display Description - Extech Instruments RH390-NIST User Manual

Introduction

Congratulations on your purchase of the Extech RH390 Digital Psychrometer. This device
measures Humidity, Air Temperature, Dew Point temperature and Wet Bulb temperature.
Advanced features include Data Hold, Auto Power Off, and MAX/MIN reading. Careful use of this
meter will provide years of reliable service. Please visit our website (www.extech.com) to check
for the latest version of this User Guide, Product Updates, and Customer Support.

Meter Description

Humidity & Temperature Sensor
1.
LCD Display
2.
Power ON/OFF button
3.
°F/°C/WBT (wet bulb)/Dew Point button
4.
MIN/MAX button
5.
HOLD/Backlight button
6.
Note: The battery compartment is located
on the rear of the instrument

Display Description

Relative Humidity %
1.
Dew Point
2.
Wet Bulb
3.
°C/°F
4.
Temp/WB/DP Display
5.
Maximum
6.
Minimum
7.
Low Battery
8.
Hold
9.
RH% Display
10.
Auto Off
11.
1
2
3
6
5
4
9
10
8
11
2
6 7
MAX MIN
°C °F
Dewpoint
WetBulb
5
RH390-EU-EN V2.3 07/13
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4
2
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