MODEL 315 HUMIDITY TEMPERATURE METER
4.0 Operating Instructions:
4.1 Preparation for Measurement:
To measure ambient humidity and temperature, hold the instrument in the
environment of interest and allow sufficient time for the sensors to respond
to ambient conditions. (See Section 2.0 – Response Time.)
4.2 Power:
Press the button to turn the instrument ON or OFF.
4.3 Selecting the Temperature Scale
When first turned on, the instrument defaults to reading in Celsius (°C). The
instrument toggles between Celsius (°C) and Fahrenheit (°F) each time the
°C/°F button is pressed. The instrument remembers the scale setting when
last turned off and powers on in that setting the next time.
4.4 Data-Hold Function
The present reading is held on the display by pressing the HOLD button.
Pressing the HOLD button again releases the hold function and returns the
instrument to continuous reading.
In the HOLD mode, the UREL, MAX MIN and °C/°F buttons are disabled,
as indicated by two consecutive beeps when pressed.
4.5 Relative Operation
Pressing the UREL button internally memorizes
the present
reading and
the main display shows the difference between the new reading and the
memorized value. Press the UREL button again to exit the Relative
operation.
4.6 MAX/MIN Operation
Press the MAX MIN button to enter the MAX/MIN mode. In this mode, both
the maximum and minimum values are simultaneously retained in memory
and updated with every new data sample. The instrument first enters the
MAX mode, and the MAX symbol and value are both displayed. Pressing
MAX MIN again advances the display to the MIN symbol and value. The
next press of the MAX MIN button will cause both the MAX and MIN
symbols to blink. This indicates that the maximum and minimum values
have been updated in memory and the displayed reading is the present
value. Each successive
press of the MAX MIN button circulates the display
mode among these options. To exit the MAX/MIN mode, press and hold
MAX MIN for two seconds.
In the MAX/MIN mode, the, UREL and °C/°F buttons are disabled, as
indicated by two consecutive beeps if pressed.
3
MODEL 315 HUMIDITY TEMPERATURE METER
4.7 Auto Power Off
By default, the instrument powers on in the ‘Auto Power Off’ mode and will
automatically shut off 30 minutes after the last key operation.
To disable this feature, press and hold the HOLD button and then power on
the meter. Two successive beeps indicate that ‘Auto Power Off’ is disabled.
4.8 Low Battery Condition
When the battery voltage is at or below the minimum for proper operation,
the symbol will show on the display indicating that the battery must be
replaced.
4.9 Calibration Points:
Room temperature: 23°C ± 5°C
Temperature calibration points: 0°C and 40°C
Humidity calibration points: 32.8% RH@25°C and 75.3% RH@25°C
4
5.0 Calibration Procedure:
Note: Conduct temperature calibration before humidity calibration.
5.1 Temperature Calibration
1. Turn the unit off. Press and hold the HOLD and °C/°F buttons. While
these two buttons are pressed, turn the power on. Release all buttons
and all the segments on the display will blink.
2. Within 3 seconds of releasing these buttons, again press the °C/°F
button to enter the calibration mode, or the instrument will revert to
normal operating mode.
3. Upon entering the calibration mode, ‘CAL1’ will appear on the second
display.
4. Insert the probe into a temperature-controlled chamber at 0°C (32°F)
and allow the system to stabilize for 10 minutes. Press the MAX MIN
button to initiate calibration. A single long beep will indicate calibration
is complete, and the instrument will advance into the ‘CAL2’ mode, as
indicated on the second display.
5. Insert the probe into a temperature-controlled chamber at 40°C (104°F)
and again allow the system to stabilize for 10 minutes. Press the
MAX MIN button to initiate calibration. A single long beep will indicate
calibration is complete, and the instrument will revert to normal
operating mode.