MODEL 308 MINI DUAL CHANNEL THERMOMETER
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4.0 Operating Instructions4.1 Preparation for Measurement
Plug the first thermocouple into the socket marked T1, taking care to
observe the polarity of the thermocouple pins. If dual sensors are being
used, plug the second thermocouple into the socket marked T2.
4.2 Power
Press the button to turn the thermometer ON or OFF.
4.3 Selecting the Temperature Scale
When first turned on, the instrument defaults to reading in Fahrenheit (°F).
The instrument toggles between Fahrenheit (°F) and Celsius (°C) each time
the °C/°F button is pressed.
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 zeroes the display and internally stores
the
present
reading as a reference for subsequent measurements. The main
display now shows the difference between the stored value and the new
reading.
Press the UREL button again to exit the Relative mode.
4.6 MAX/MIN Operation
Press the MAX MIN button to enter the MAX/MIN mode. In this mode, 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 flash. This indicates that the maximum and minimum values
have been updated in memory and the displayed reading is the present
temperature. Each successive press of the MAX MIN button circulates the
display mode among these options. To exit the MAX/MIN mode, press and
hold the MAX MIN button for two seconds.
In the MAX/MIN mode, the UREL and °C/°F buttons are disabled, as
indicated by two consecutive beeps when pressed.
MODEL 308 MINI DUAL CHANNEL THERMOMETER
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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
Calibration is conducted by adjusting the following potentiometers to within
the tolerances shown.
(Ambient Temperature: 23 ± 3°C)
Input Adjust VR Tolerance
0 °C VR3 ± 0.1 °C
190 °C VR2 ± 0.1 °C
1000 °C VR1 ± 1 °C
1900 °F VR4 ± 1 °F
A simple single point calibration may be performed by adjusting VR3 to
0 °C with thermally stabilized ice water.
Appendix: Thermocouple Probe Specifications
Model Range Tolerances Description
TP-K01
Wire probe
-50°C to 200°C
-58°F to 392°F
±2.2°C or ±0.75%
(±3.6°F or ±0.75%)
Teflon insulation. Maximum
insulation temperature: 260°C
TP-K01:
Probe for general condition measurements,
especially for complex and hard to reach
places