Hanna Instruments HI 221 - Manual (Page 25)

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The instruments are factory calibrated for temperature.
Hanna’s temperature probes are interchangeable and temperature calibra-
tion is not necessary when replaced.
If the temperature measurements are not accurate, temperature recalibration
should be performed.
For an accurate recalibration, contact your dealer or the nearest Hanna
Customer Service Center, or follow the instructions below.
• Switch off the instrument.
• Prepare a vessel containing ice and water and another one containing hot
water (around 50 °C). Place insulation material around the vessels to
minimize temperature changes during calibration.
• Use a ChecktempC or a calibrated thermometer with a resolution of 0.1 °C
as a reference thermometer.
• Immerse the temperature probe and the ChecktempC into the vessel
TEMPERATURE CALIBRATION
(FOR TECHNICAL PERSONNEL ONLY)
SERIAL COMMUNICATION BAUD RATE SET
Press the CAL key when the baud rate is displayed. The baud rate (600,
1200, 2400, 4800 or 9600) will begin to blink.
Press the ARROWkeys to change the baud rate.
Press the CFM key to save the modified baud rate or press the CAL key to
cancel without saving the baud rate.
SERIAL COMMUNICATION COMMAND PREFIX SET
Press the CAL key when the command prefix is displayed. The command prefix
(0 to 47) will begin to blink.
Press the ARROWkeys to change the command prefix.
Press the CFM key to save the modified command prefix value or press the CAL
key to cancel without saving the command prefix.
Note: See the PC Interface section on page 28 for a complete explanation. The
command prefix must be 16 if the HI 92000 PC software is used.