Hanna Instruments HI 120 - Manual (Page 40)

40
TEMPERATURE CALIBRATION
(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 )
All the instruments are factory calibrated for temperature.
Hanna’s temperature probes are interchangeable and no temperature
calibration is needed when they are replaced.
If the temperature measurements are inaccurate, temperature recalibration
should be performed.
For an accurate recalibration, contact your dealer or the nearest Hanna
Customer Service Center, or follow the instructions below.
• Prepare a vessel containing ice and water and another one containing
hot water (at approximately 50 ºC or 122 ºF). Place insulation material
around the vessels to minimize temperature changes.
• Use a calibrated thermometer with a resolution of 0.1 ºC or 0.1 ºF as a
reference thermometer. Connect the HI 7662-T temperature probe to the
appropriate socket.
• With the instrument off, press and hold down the CAL & keys, then
power on the instrument. The “CAL” tag will appear and the secondary
LCD will show 0.0 ºC or 32.0 ºF. The primary LCD will display the
measured temperature or the ”----” message, if the measured tempera-
ture is out of range.
• Immerse the temperature probe into the vessel with ice and water as
close as possible to the reference thermometer. Allow a few seconds for
the probe to stabilize.
• Use the ARROW keys to set the reading on the secondary LCD to that of
ice and water, measured by the reference thermometer. When the reading
is stable and close to the selected calibration point, “CFM” tag will blink.
• Press CFM to confirm. The secondary LCD will display
50.0 ºC or 122.0 ºF.
• Immerse the temperature probe into the second vessel
as close as possible to the reference thermometer.
Allow a few seconds for the probe to stabilize.
• Use the ARROW keys to set the reading on the secondary LCD to that
of the hot water.
• When the reading is stable and close to the selected calibration point,
“CFM” tag will blink.
CFM