Hanna Instruments HI 504 User Manual

Page 10

• When the reading becomes stable, if the ORP value is

close to the calibration point, the “CFM” indicator starts
blinking; otherwise the “WRONG” indicator blinks and
the “CAL” is fixed on.

• In the first case press CFM 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 CFM the secondary LCD will
display the second calibration point.

• In the second case (blinking “WRONG”) the meter will

remain in the WRONG state until the reading becomes
unstable or the calibration mode is exited by pressing the
CAL key.

• For the second calibration point it is possible to choose

between 350 mV or 1900 mV. Pressing the

æ or key the

value on the secondary LCD will switch between the two
possibilities.

• Once selected the second calibration point, set the HI

931001 (350 mV) or HI 8427 (350 or 1900 mV) simula-
tor to the same value and the calibration proceeds as for
the first point.

Note

In ORP calibration there is no time-out.

ANALOG OUTPUT CALIBRATION

The instrument can be provided with one or two analog out-
puts, each of them can be calibrated.

• Connect an Ammeter or the HI 931002 calibrator to the

analog output to measure the current erogated by the meter.

• Enter the calibration mode and move through the menu

using the

æ or key until “Out 1” or “Out 2” message

appears on the primary LCD.

• The pH calibration value will switch

to 7.00, the first digit starts blinking
and it is possible to change its value
simply using the

æ or key.

• Once selected the first digit value, press the key: the first

digit will be fixed and the second one will start blinking.
Pressing of the key repeatedly will result on circularly
moving on the secondary LCD.

• When the desired calibration value is reached (must be

within 0.00 to 16.00 pH), press the CFM key to confirm
and the calibration will proceed as described above.

• If the selected value is outside boundaries, the confirma-

tion is not accepted and the first digit keeps blinking (waiting
for confirmation of a valid value).

Note

If SETUP key is pressed instead of CFM, the calibration value
selection is aborted and the meter reverts back to a two-point
calibration.

ORP CALIBRATION

To perform ORP calibration it is necessary to connect an HI
931001 or HI 8427 simulator to the BNC socket.

The meter has to be set as ORP controller.

• Set item I.04 to “OFF” to disable the Matching Pin.

• A two-point calibration has to be performed: the first point

value is 0 mV and the second one can be chosen between
350 mV and 1900 mV.

• Enter the calibration mode, select the ORP calibration (use

the

æ and keys to move through setup menu) and press

the CFM key.

• Set the HI 931001 or HI 8427 simulator to 0 mV.

• The primary LCD will display the cur-

rent mV measure and the secondary
LCD will show the first calibration
point (0 mV).