Hach 8450, Instrument Manual

Page: 34 / 66

Page 34
Frequency of Calibration
16116Operation.fm
Section 3
3.12 Frequency of Calibration
The frequency of calibration for Series 8400 Chlorine monitors depends upon
the environmental conditions of the probe. It is recommended that the unit be
monitored for reading fluctuations or erroneous outputs for the first several
months of operation.
In addition to the above, the instrument should be recalibrated:
• After initial installation
• Anytime probe is rebuilt
• If the probe has been disconnected or unpowered
• If erratic readings occur
3.13 Considerations Before You Calibrate
The following operational guidelines are important considerations for fast and
accurate calibration of the meter. They are particularly important when
attempting to SPAN calibrate the meter to concentrations below 1.00 ppm
(1.00 mg/L).
3.13.1 Probe Preparation and Setup
Ensure that the probe has been properly prepared and installed. If the probe
has just been rebuilt, connect the probe to the monitor, apply system power,
and permit it to stabilize for at least 12 hours in water. Alternatively, the Probe
Polarizer Unit (Cat. No. 16239) can be used to prepare the probe for use. The
advantage of the Polarizer unit is that a monitor does not have to removed
from operation while another probe is being conditioned. Condition the probe
for 12 hours on the Polarizer unit (see
Figure 23 ).
Figure 23 Probe Polarizer Unit
Probe Plug
Deionized Water