Hanna Instruments HI 504 User Manual

Page 12

is exited (by pressing the CAL key).

• When performing the second calibration point, it is pos-

sible to choose between two values, 25°C and 50°C. Pressing
the

æ or key the value on the secondary LCD will switch

between the two possibilities.

• Once selected the value, immerse the temperature probe

in the second beaker as near as possible to the Checktemp
and the calibration procedure will be the same as for the
first point.

VOLT CALIBRATION

The instrument is factory calibrated; however the user may
also perform the Volt calibration, which is a procedure avail-
able for the meter configured as pH controller only.

During pH measurements the instrument reads a mV value
from the electrode and then converts it into a pH value.

• Set item I.04 to “OFF” to disable the Matching Pin.
• Connect a HI 931001 or HI 8427 simulator to the BNC

socket.

• Once entered the calibration mode,

move through the menu with

æ or

key, select the Volt calibration (the

primary LCD shows “UOLt” mes-
sage) and confirm it by pressing the
CFM key.

• After confirmation the primary LCD

will show the actual mV value and
the secondary LCD will display the
first calibration point.

• The calibration is performed over two points, 0 and 350 mV.
• Set the HI 931001 or HI 8427 simulator to 0 mV.
• When the reading becomes stable, if the measured 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 to confirm the current buffer or right to escape” (to
prevent from confirming the calibration point inadvertently).

• Pressing again CFM the secondary LCD will display the

second calibration point.

• Set the HI 931001 or HI 8427 simulator to 350 mV and

follow the same procedure as for the first point.

• If the measured value is not close to the calibration value,

the meter will remain in the WRONG status until the read-
ing becomes unstable or the calibration mode is exited (by
pressing the CAL key).