Hach ORBISPHERE 3658 Manuel D'utilisation Simplifié page 19

Figure 3 Calibration setup diagram
1 Needle valve
2 Accurate pressure gauge
3 Flow chamber
The procedure requires a source of pure CO
central entry port of the flow chamber, an accurate pressure gauge (better than ± 2%) at the exit of
the flow chamber, a needle valve to control the flow on exit, and a beaker of water to monitor the gas
flow. Figure 3 above illustrates the calibration setup.
6.2.3 Calibrating in a liquid CO
Effective calibration is critical to the performance of any analytical instrument, and Hach Lange
recommends the use of its High Precision Calibration Kits which are designed to give a traceable and
trustworthy calibration standard with defined CO
The calibration solution is quick and easy to prepare, and calibration can be undertaken in less than
three minutes. Simply replace the package sample in your piercing device with the calibration bottle
containing the dissolved CO
1. Set the gas measurement phase to Dissolved (see
set the calibration medium to In a liquid or a gaseous sample at known concentration (see
Calibration medium
2. Press the CAL button. Remember, this button may have been locked out to prevent an accidental
reset (see Locking out the instrument's CAL button
3. A brief clearing [---] message appears.
4. Press CAL again within a 3 second period. The instrument then displays the concentration of
CO based on the last value of the calibration coefficient.
2
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. (50% on the
32311 Flow Meter) and stable.
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.
2
solution
2
solution.
2
on page 17).
4 Pressure valve
5 Beaker of water
6 Pure gas supply
gas (regulated by a pressure valve) connected to the
content of ± 0.5%.
2
Gas measurement phase
on page 17).
on page 16) and
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