Measurement Units; Rolling Average - Hach ORBISPHERE 3654 Manuel D'utilisation De Base

6.4.2 Measurement units

Choose the Configuration, Units menu to select gas measurement units, temperature
measurement units, and the liquid medium in which you are measuring.
Using this dialog box, you can select:
• The Gas units in which gas concentrations are to be displayed
• For dissolved measurements: g/kg, % (by weight), V/V, cc/kg, mL/L, ppm/ppb, ppm or
mg/100mL
• For gaseous measurements: %/ppm (by volume), % (by volume), kPa/Pa, kPa, bar/mbar, bar,
bar20/mbar20 or bar20
• The Liquid medium for dissolved gas concentration measurements: Water, Beer, Cola
• The Temperature units for display: °C or °F
6.4.3 Membrane selection
You may find it necessary to use a different type of membrane for different applications. Naturally,
with any membrane change, you will need to re-calibrate. You should also consider the changes in
required flow rates and response times, which are listed in sensor specifications. Refer to
calibration on page 21.
To re-configure the analyzer, choose Configuration, Membrane to bring up the box which reveals the
membrane models available.
Membrane 29561A is available for any gas measurement. Membranes 2935A and 2952A are
available for H measurement only. Choose OK when the desired membrane is selected.
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Note: Only those membranes applicable to your system can be selected. All other membranes are grayed out.
6.4.4 Automatic data acquisition - Setting sampling intervals
The instrument can perform as a standalone data acquisition device, automatically recording gas
measurements with the date and time, and storing up to 500 of these values. Choosing the Hach
3654 program's Configuration, Sampling Rate menu lets you select time intervals (acquisition rate)
for this storage capability.
Use the slide bar to view and select a sampling rate, from 15 seconds to 1 hour. The selected rate is
shown in the Acquisition rate window. Click OK to save this rate. Once your choice is made, the
instrument can be used independently of the Hach 3654 program for data acquisition. Refer to
Automatic data acquisition
Note: The Acquisition rate set via this menu is independent from the monitoring chart updating rate in
measurements in real-time
the chart updating rate is used only for displaying real-time results via the monitoring chart.
6.4.5 Calibration medium
You can use the Configuration, Calibration medium command to select how the sensor is to be
calibrated.
Choose either in pure H
known concentration of gas. Choose OK when the desired medium is selected.
Note: You can create a solution having a known H
measured temperature and pressure. Hach Lange can provide equipment for generating such a solution.
Alternatively, you can analyze a carbonated beverage independently by other acceptable means.
6.4.6 Locking out the instrument's CAL button
You can use the Configuration, Sensor Calibration Status menu to prevent an accidental sensor
recalibration from the instrument keyboard.
Choose Disabled to lock out the keyboard CAL button. To unlock this capability, choose Enabled.
Choose OK when the desired mode is selected.

6.4.7 Rolling average

Choose Rolling Average Status from the Configuration menu to enable or disable the averaging of
gas concentration measurements.
To enable averaging on three successive gas measurements, choose Enable. Choose Disable to
disable rolling average.
20 English
on page 15.
on page 17. The sampling rate menu applies only to automatic data acquisition, while
or N gas at atmospheric pressure or in a liquid or gaseous solution at a
2 2
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or N concentration by dissolving H
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Sensor
Monitoring
or N in water at a
2 2