Hanna Instruments HI 504 User Manual

Page 11

TEMPERATURE CALIBRATION

• Prepare a beaker containing

crushed ice and water at 0°C (32°F)
and another one with hot water at
25°C (77°F) or 50°C (122°F).

• Use a Checktemp or another cali-

brated thermometer with a
resolution of 0.1° as a reference
thermometer.

• Immerse the temperature probe in

the beaker with ice and water as
near to the Checktemp as possible.

0 °C

(32 °F)

°C

50 ºC

(122 ºF)

°C

0 °C

(32 °F)

°C

• Once visualized the selected output, press the key to

choose the range of the analog output (0-20 mA or 4-20
mA); then press the CFM key to confirm the choice.

• Once selected and confirmed the

range for the analog output, the
secondary LCD shows the first point
of calibration (1 or 4 mA) and the
primary LCD displays the range of
the actual calibration.

• With the tester check the real current value provided by the

instrument at the output port. If this value is different from
the expected one, it is possible to change the current
erogated by the instrument pressing the

æ or key.

• Adjust the value until it matches with the first point of cali-

bration, then press CFM to confirm. The instrument will
turn to the second calibration point (20 mA).

• The calibration procedure is the same as for the first point.

• Once the instrument is calibrated for both points (and con-

firmed), it will exit from the calibration menu.

Note

The instrument can support Pt100 or Pt1000 temperature

sensor and calibration can be performed with anyone of these
two probes.

• After entering the calibration mode, move through the menu

(using the

æ or key) to choose the temperature and the

correct kind of used probe; the pri-
mary LCD shows “°C” and the
secondary LCD gives indication
about the kind of probe (“100” in-
dicates a Pt100 probe, while
“1000” stands for a Pt1000
probe).

Press the CFM key to confirm selection.

• The calibration has to be performed

over two points: the first point has to
be 0°C and the second one can be
chosen between 25°C and 50°C.

Once confirmed the type of calibration, the primary LCD

will display the current temperature measure and the sec-
ondary LCD will show the first calibration point (0°C).

• When the reading becomes stable, if the temperature value

is close to the calibration point the CFM tag starts blink-
ing, otherwise the WRONG indicator will flash.

• In the first case press the CFM key to confirm calibration.

The meter will proceed showing the scrolling message “Press
CFM again to confirm the current buffer or right to es-
cape” (to prevent from confirming the calibration point
inadvertently).

• Pressing again the CFM key, the sec-

ondary LCD will display the second
calibration point.

• In the case the measured temperature is not close to the

calibration value, the meter remains in the WRONG status
until the reading becomes unstable or the calibration mode