27
CALIBRATION
The controller is factory calibrated for mV and temperature
inputs as well as for the analog outputs.
The user should periodically calibrate the instrument. For
greatest accuracy, it is recommended that the instrument is
calibrated frequently.
It is possible to standardize the electrode with only one buffer,
preferably close to the expected sample value (one-point
calibration), but it is always good practice to calibrate in
at least 2 points.
pH CALIBRATION (for pH500 Series only)
The pH controller can be calibrated through a one-point,
two-point or three-point calibration. You do not need to enter
the method chosen, simply exit the
calibration mode, by pressing CAL,
when the desired number of points
has been calibrated.
The calibration points for pH500 are pH4.01, pH7.01
and pH10.01 (at 25 °C). The sequence proposed by the
controller is pH7.01, pH4.01, pH10.01. However, the user
can change this sequence by means of the
and
keys.
The electrode must be kept hydrated at all times and defi-
nitely prior to calibration. The temperature probe should also
be connected to the process meter. The meters are equipped
with a stability indicator. The user is also guided with indi-
cations on the display during the calibration procedure.
Initial Preparation
Pour small quantities of pH7.01 (
HI7007
) and pH4.01
(
HI7004
) and/or pH10.01 (
HI7010
)
solutions into individual beakers. If
possible, use plastic beakers to mini-
mize any EMC interference.
HI7007
HI7004
HI7004
