Hach Ultra ORBISPHERE 511 Quick Manual page 4

Continuous Mode vs. Sample Mode
The continuous mode is typically used for process
measurement, whereas sample mode is aimed at
lab measurements of small volume individual
s a m p l e s s u c h a s c a n s o r b o t t l e s . T h e
measurement mode is a parameter defined for
the entire instrument, not for each channel.
In continuous mode, measurements are taken
every 2 seconds. In sample mode, measurements
are initiated by the user when the sample to be
measured has been prepared. TPO or TPA
c a l c u l a t i o n i s o n l y a v ai l a bl e fo r p or t ab l e
instruments in sample mode.
Measurement Mode Configuration
• Measurement mode:
Continuous for on line process
Sample for lab sample analysis (portable
instruments only)
• Selection of units for barometric and
external pressure and temperature
Stop Criteria Configuration (portable only)
Available in sample measurement mode for
configuring the stop criteria for each channel:
• Above threshold: The stop criteria is met
when the gas concentration is greater
than that entered in "Threshold".
• Below threshold: The stop criteria is met
when the gas concentration is smaller
than that entered in "Threshold".
Page 4
Measurement
• Stability: The stop criteria is met when the
variation of the gas concentration is
smaller than that entered in "Variation".
• Time: The stop criteria is met when the
elapsed time reaches the "Max. time"
parameter.
The parameter "Max. time" is the maximum time
allowed to reach the target. When this value is
reached the measurement stops.
The "Time filter" allows filtering the stop criteria.
Measurement is stopped when the stop criteria is
fulfilled for a time greater than this parameter.
If TPO or TPA calculation has been enabled, then
when the stop criteria is reached, a screen is
displayed to input the package size and volume of
liquid in the package before computing the TPO
or TPA value.
Measurement Configuration (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
• 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.
• Thermal cutoff: To protect the sensor, the
thermal cutoff function allows for setting a
sample high temperature limit. If
exceeded the electrical signal to the
sensor is cut off, the measurement
session is suspended and the system
displays a "HOT" alarm message.