KROHNE Summit 8800 Vol 2 - Manual (Page 79)

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08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 STREAM CONFIGURATION 06
Dual frequency deviation The threshold value (+/-) for the deviation of the two frequencies
above which an alarm is raised.
Dual frequency pulse limit Used to monitor pulse fidelity to alarm an added or missing
pulse caused by electrical transients and electronic failures. This
monitoring function allows the user to reduce the flowmeter
uncertainty factors.
Dual frequency pulse interval The time between pulses sequences. This is the maximum allowable
time for pulse limits before an alarm is activated.
Dual frequency failure limit Lack of continual pulses before the meter is deemed failed and
raises an alarm
Dual frequency direction change Number of pulses allowed in opposite flow to determine the
direction of the medium flowing in the meter.
Dual frequency min. frequency Low cut-off frequency. This is frequency below which the flow will be
considered 0.
6 .2 .2 .4 Meter Correction
Define the correction for expansion of the meter body for pressure and temperature to maximize
the ultrasonic meter accuracy as the properties of the UFM, and it’s connection to the main
stream pipe may change.
Figure 71 Examples ultrasonic meter correction section
Selection of any Pressure or Temperature expansion correction:
• None
• Correction for Flanged
• Correction for Welded
• Correction in accordance with ISO 17089
• Cryogenic
With as parameters:
Flanged & Welded ISO 17089 Cryogenic
Thermal expansion, α Thermal expansion, α NIST constants A to E
Reference pressure, p0 Reference pressure, p0
Reference temperature, t0 Reference temperature, t0
Spool piece inner diameter Inside pipe radius
Wall thickness Outside pipe radius
Modulus of elasticity, E UFM poison ratio, σ
Modulus of elasticity, E