Hanna Instruments HI 2550 User Manual

Page 42

The instrument has two temperature channels: one that measures the

temperature from the HI 7662 probe while the instrument is in pH/mV

range and the other that measures temperature from the EC probe while

the instrument is in EC/TDS/NaCl range.
All the instruments are factory calibrated for temperature on both channels.
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 (around 50 ºC). Place insulation material around the vessels

to minimize temperature changes.

• Use a calibrated thermometer with a resolution of 0.1 ºC as a

reference thermometer. Connect the HI 7662 probe to the appropriate

socket for the pH temperature channel or the HI 76310 probe for the

EC temperature channel.

• With the instrument off, press and hold down the CFM & SETUP

keys, then power on the instrument to calibrate the pH temperature
channel or &RANGE keys and then power on the instrument to

calibrate the EC temperature channel. The “CAL” tag will appear

and the secondary LCD will show “0.0 ºC“.

• Submerse the temperature probe (or EC probe) in the vessel with ice

and water as near as possible to the calibrated 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 calibrated thermometer. When
the reading is stable and close to the selected calibration point,
“READY” tag will appear and “CFM” tag will blink.

• Press CFM to confirm. The secondary LCD will show

“

50.0

“

TEMPERATURE CALIBRATION

(((((for technical personnel only

for technical personnel only

for technical personnel only)))))

CAL