Hach ORBISPHERE 3658 Basic User Manual page 18

In short these calibration kits offer:
• Traceable and accurate calibration
• Quick and easy solution preparation
• Eliminates handling of aggressive chemicals which are usually required in reference preparation
• High and low level kits are available to ensure accuracy in the appropriate measurement range
Once the solution has been prepared in the calibration bottle, it can be used in the standard package
piercer in place of the sample package.
Using a source of pure CO
Ensure that the purge cycle is running correctly by placing the purge gas exit tubing into water. This
rate should be more than four bubbles during the purge which lasts for 4 seconds. This purge cycle is
repeated every 20 seconds.
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.
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
18 English
gas
2
2
solution
2
solution.
2
on page 16).
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 16).
on page 15) and