Hanna Instruments HI 98701 - Manual (Page 8)

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The meter is factory calibrated. However, as a general rule, it is
recommended to have all thermometers recalibrated at least once a
year. It is recommended that recalibration is performed by authorized
technical personnel only to assure the accuracy of the instrument.
Contact the nearest HANNA service center for an accurate annual
recalibration.
Both thermocouple inputs and cold junction can be calibrated.
A two-point calibration at 0.000 mV and 41.269 mV has to be
performed in order to store the new thermocouple calibration data in
memory. Cold junction calibration is at one point only, corresponding
to the environment temperature.
COLD JUNCTION CALIBRATION
1. Press CH/TIME or TEMP/TIME until the cold junction temperature
reading is displayed.
2. Press ALT, CFM and PAPER simultaneously while the meter is not
printing nor logging to enter calibration mode.
3. User is prompted to enter password if it has been set to a value
different from 0000, otherwise skip to step 6.
4. Enter the password using the arrow keys.
5. Press ALT and CFM to confirm the password or CH/TIME or TEMP/
TIME to exit.
6. If password is correct or not set, the meter
will display "25.0°C" (or "77.0°F"), with
the "2" (or "7") blinking, on the upper
LCD and "C CJ" on its lower part; if
wrong, it will return to measurement mode without any message.
7. Enter the actual cold junction temperature (the environment tem-
perature measured with a reference thermometer) using the arrow
keys (temperature must be between 0 and 50 °C).
8. When the "S" symbol blinks in the lower
LCD, the reading is stable and calibration
can be confirmed pressing ALT and CFM.
9. The LCD will display CALC for a few seconds and then the meter
returns to normal operational mode.
TEMPERATURE CALIBRATION PROCEDURE
( f o r t e c h n i c a l p e r s o n n e l o n l y )
To prepare the instrument for use, choose the most appropriate
temperature probe for your application (see "Accessories" section) and
connect it to the instrument.
The factory default thermocouple type is K, represented with the "dF"
indication. If needed, select a different type (J and T types also
available) through setup code #70.
With the meter facing you, channel #1 is the first connector on the
top left hand side.
Press the ON/OFF key to power on the instrument, and insert the
probe in the sample to be tested and allow the reading to stabilize.
The temperature is displayed on the upper
LCD. The lower LCD shows the selected chan-
nel number (HI 98704 and HI 98804 only).
The meter selects channel 1 as default. Press
CH/TIME (HI 98704 and HI 98804) or TEMP/
TIME (HI 98701 and HI 98801) to view the
reading of the other channels, the cold junc-
tion temperature, date and time in the
following order:
• channel 2 temperature reading (4-channel versions only)
• channel 3 temperature reading (4-channel versions only)
• channel 4 temperature reading (4-channel versions only)
• cold junction temperature reading ("C J" appears in the lower LCD)
• date
• time
Pressing CH/TIME or TEMP/TIME again, the meter returns to channel
1 temperature reading.
If the reading is out of range or the probe is
not connected to a channel, the LCD will
display dashes in place of the reading.
Note: To choose between "°C " and "°F" unit, enter the setup code 71.
Note: The meter is factory calibrated.
After 1 year since last thermocouple
calibration the "DATE" symbol starts
blinking on the LCD to warn the user
that a recalibration is suggested to
maintain the meter accuracy.
Contact the nearest HANNA service center for an accurate
recalibration of your thermometer.
TAKING TEMPERATURE MEASUREMENTS