Calibrating In A Liquid H Or N Solution - Hach ORBISPHERE 3654 User Manual

6.2.4 Calibrating in a liquid H
The sensor can be calibrated in a standard liquid solution that has a known concentration of H
or N
2
measured temperature and pressure. Alternatively, analyze a carbonated beverage
independently by some acceptable means.
Note: A flow rate lower that 150 ml/min can be used for the calibration, but you must ensure that all
measurements made after the calibration are made at exactly the same flow rate as is used for the
calibration. To ensure accurate results it is recommended to use a model 32311 Flow Meter. Refer to
32311 flow meter on page
If the instrument makes two consecutive measurements with less than 1% difference, it
calibrates against this stabilized value. The LCD then displays the message [CAL] to indicate
calibration has been successfully completed
If the calibration does not complete, the LCD displays the message [Err]. The reason for this
calibration error is either that the measured gas partial pressure is under 5 mbar, or that a wrong
instrument key was pressed during the calibration steps.
or N solution
2 2
You can create a solution with a known concentration by dissolving H
.
37.
1. Set the gas measurement phase to Dissolved
and set the calibration medium to In a liquid or
a gaseous sample at known concentration,
Refer to Calibration medium on page
2. Press the CAL button. Remember, this button
may have been locked out to prevent an
accidental reset. Refer to
instrument's CAL button on page
3. A brief clearing [---] message appears.
4. Press CAL again within a 3 second period. The
instrument then displays the concentration of H
or N , based on the last value of the calibration
2
coefficient.
5. Modify this reading using the Up/Down Arrow
keys until the displayed concentration agrees
with that of the calibration solution.
6. Press CAL again.
7. Start the flow of the standard (calibration)
solution through the flow chamber. Adjust the
flow until the liquid is foam-free. The flow rate
should be a minimum of 150 ml/min and be
stable.
Calibrations
2
or N in water at a
2 2
29.
Locking out the
30.
2
Model
35