Hach-Lange ORBISPHERE Model 51x User Manual - Manual (Page 55)

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Measurement Menu
6.2 Measurement configuration
TPO and TPA parameters (portable instrument)
The parameters required for TPO and TPA calculation are the same.
•
Overflow volume : Total package size
• Net content volume : Volume of liquid in the package
Press the Compute button to calculate the TPO or TPA. The parameters can be changed and the value
recalculated if necessary.
TPO values are displayed in ppm, TPA values in mL.
To store the measurement, press the OK button.
Stop criteria configuration (portable instrument)
Press the Stop criteria button.
Note:
The parameters available for configuration depend on the type of stop criteria being defined.
Available in “Sample measurement mode” (see Instrument configuration on page 52 ), this setting allows
configuration of the stop criteria for each channel:
•
Above threshold : The stop criteria is met when the gas concentration is greater than the parameter
entered in "Threshold”
• Below threshold : The stop criteria is met when the gas concentration is lower than the parameter
entered in "Threshold”
• Stability : The stop criteria is met when the variation of the gas concentration is smaller than the
parameter entered in "Variation"
• Time : The stop criteria is met when the elapsed time reaches the “Max. time” parameter.
Note: The number of samples taken into account to compute the "Variation" can be adjusted using the
parameter "Depth".
•
The parameter "Max. time" is the maximum time allowed to reach the target. If “Time” is not the type
of stop criteria, then when this delay has elapsed, the measurement stops and the message
“aborted” is displayed.
• The time filter allows you to filter the stop criteria. The sample mode is stopped when the stop criteria
is fulfilled for a time greater than the parameter "Time Filter".
As an example, if criteria is set to "Above threshold" and “Time Filter” is set to 10 sec. the
measurement stops when the gas concentration is above the "Threshold" for more than 10 seconds.
EC sensor
• Sensor’s membrane number selection
• Medium : Liquid or gas phase.
• Gas unit type : Partial, Fraction, Dissolved.
• Gas unit : The list of available units depends on unit type selected above.
Note: This is the gas concentration measured by the EC sensor. When a composite unit is selected (e.g.
ppm-ppb) the unit will change depending on the range of the value to display.
•
Liquid : When medium is liquid, select water or a liquid with a different solubility (if available).
• Display resolution : Maximum resolution depends on gas, membrane and unit. A maximum of 5
digits can be displayed. Decimals can be limited to 0, 1, 2 or 3 decimals for easier reading. That does
not affect the actual resolution of data measured and stored, but only the data displayed.
• Thermal cutoff : To protect the sensor, the thermal cutoff function allows for setting a sample high
temperature limit. If exceeded (during a Cleaning In Place cycle for example) the electrical signal to
the sensor is cut off, the measurement session is suspended and the system displays a “HOT” alarm
message. The system resumes when temperature drops to 90% of the specified cutoff temperature.
•
Thermal cut off options : Disabled / enabled.
• Thermal cut off temperature : To be set according to conditions.
TC sensor
The measurement configuration for a TC sensor is the same as for an EC sensor with the addition of one
extra selection criteria:
•
Purge gas : From the drop-down list, select the purge gas being used for the TC sensor.