RH490 Datasheet, PDF (6/7 Pages) Extech Instruments Corporation. – Precision Hygro-Thermometer

Minimum (MIN) Maximum (MAX) Function
The MIN/MAX mode allows the user to view only the lowest (MIN) or highest
(MAX) readings.
1. Press the ”H MAX MIN” button twice and “MIN” appears on the display. The
LCD is now displaying the minimum value recorded in both the top and
bottom display. The display will not change until a lower reading is
registered.
2. Press the ”H MAX MIN” button again and “MAX”
appears on the display. The LCD is now displaying
the maximum value recorded in both the top and
bottom display. The display will not change until a
higher reading is registered.
3. To exit the MIN/MAX mode, press the ”H MAX
MIN” button again. The “MAX” icon will disappear.
Note: Max and Min values are recorded into memory
while the meter is on. The values are erased
when power is turned off.
Backlight
Press and hold the light button “ “ until the backlight turns on. To turn the
backlight off, press and hold the light button “ “ until the backlight turns off.
Automatic Power OFF
The meter has a default setting that automatically shuts the meter off after 10
minutes (indicated by the symbol on the display).
This battery saving feature can be disabled.
To disable the auto power off function, press and hold the ”H MAX MIN” hold
button while powering on. The symbol will not appear when auto power off
has been disabled.
The meter will revert to the default auto-off mode when powered off.
Maintenance
Cleaning and storage
1. The meter should be cleaned with a damp cloth and mild detergent when
necessary. Do not use solvents or abrasives.
2. Store the meter in an area with moderate temperature and humidity (refer to
the operating and storage range in the specifications chart earlier in this
manual).
Battery Replacement
When the battery becomes weak the “ “ battery symbol will appear on the
LCD. Replace the 9 Volt battery by removing the Philips head screw holding the
rear battery compartment cover to access the battery compartment. Ensure that
the compartment cover is securely fastened when finished.
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RH490 V2.0 12/06