Teledyne ULTRAFLOW 150, Operation Manual, Page: 59 / 162

SECTION 6.0, ENHANCED REMOTE PANEL W/MULTI I/O MODULE
Counts at Point 1
Temperature at Point 2
Counts at Point 2
Reference Temperature
ALARM PROPERTIES: This screen contains the alarm thresholds,
actuating variable and operating mode of the flow volume and temperature
alarms. The alarm mode and actuating variable selection apply to
instantaneous and average alarms, but the thresholds are individually
adjustable.
CONTENTS: Flow Alarm Selection
Flow Alarm Mode
Instantaneous Flow Alarm Threshold
Average Flow Alarm Threshold
Temperature Alarm Selection
Temperature Alarm Mode
Instantaneous Temperature Alarm Threshold
Average Temperature Alarm Threshold
6.4.10.2 Advanced Properties Menu
Only one Advanced Properties screen, SN Ratio Alarms, is discussed as
all others are troubleshooting in nature or require understanding outside
the scope of this manual.
SN RATIO ALARMS: This screen contains the thresholds for the
Signal-to-Noise (SN) Ratio Alarms. These alarms are useful for giving
early warning of impending transducer failure. Some important points
about these alarms are:

Site specific alarm threshold values may be developed by recording
SN Ratio data for the most challenging (typically highest flow velocity
and temperature) measurement medium conditions, then setting the
thresholds well below these levels. Typically a value of 1 is
appropriate to most sites, but some applications may lower settings.

The monitor measures instantaneous SN Ratio as a linear (not
logarithmic or decibel) value.

SN Ratio is calculated at the end of every Integration Period as an
instantaneous number. There are no average values available.

SN Ratio can be expected to vary substantially even during constant
velocity and temperature conditions, especially when the ratio is high.
Therefore, to avoid nuisance trips, it is better to set thresholds lower
than higher.
CONTENTS: SN Ratio Threshold, Downstream
SN Ratio Threshold, Upstream
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