RH350-en-GB_V2.5 11/14
5
75% Calibration
1. Insert the meter sensor into the 75% salt reference bottle.
2. Allow the meter one hour to stabilize
3. Press and hold the
[M
in
/AV
RST
]
button for 2 seconds to enter the 75% calibration.
4. “
75.3%
” (reading may vary depending on operating temperature) will flash on the LCD. After
30 minutes, the flashing will stop to indicate that the 75% calibration is complete.
5. Calibration is now complete. Turn power off.
Note: Frequently check the water level in the salt bottles. Both the 33% and 75% bottles
should be completely saturated with some water present. The bottles are sealed and not
refillable.
RS-232 PC Communications Interface
The meter is equipped with an RS-232 PC interface jack (3.5mm phono) for connection to a PC.
The cable to connect the meter to the PC is included in the optional 407752 data acquisition kit. The
kit includes Windows
TM
compatible software that allows the user to store readings in a text file and
display real-time measurements in a series of selectable formats. For more information or specific
operating instructions, refer to the User Guide included with the 407752 kit or contact Extech.
Specifications
Function
Range and Resolution
Accuracy
Humidity
0.0 to 100.0% RH
±3% RH (10 to 90%)
@ 23
°
C
Temperature (air)
-20 to 50
o
C (-4.0 to 122.0
o
F)
±1
o
C (±1.8
o
F)
Temperature (external K)
-200 to 1370
o
C (-328 to 2498
o
F)
±(0.3% rdg + 1
o
C (1.8
o
F))
Display
Triple LCD
Sensor Type
Humidity: Precision capacitance sensor
Internal Temperature: Thermistor
External Temperature: K-Type Thermocouple
Response Time
60 seconds typical
Dew Point
-68 to 50
o
C (-90.4 to 122.0
o
F) (calculated from RH and Air temperature
measurements)
Wet Bulb
-21.6 to 50
o
C (-6.88 to 122.0
o
F) (calculated from RH and Air
temperature measurements)
Low Battery Indicator
Yes
Overrange Indicator
E2 (air) E5 (T1), E8 (T2)
Underrange Indicator
E3 (air),
E6 (T1), E9 (T2)
Operating Conditions
-20 to 50
o
C (-4 to 122
o
F); < 99% RH non-condensing
Storage Conditions
-40 to 85
o
C (-40 to 185
o
F); <99% RH non-condensing
Power Supply
4 x 1.5V ‘AAA’ batteries
Battery Life
Approx. 300 hours
Dimensions / Weight
230 x 57 x 44mm (9 x 2.2 x 1.7”); 153g (5.3 oz.)
actoolsupply.com
actoolsupply.com
