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F-5500 Thermal Mass Flow Meter Manual 06/17 - 2030 / 107023
Page 59
Model F-5500
OPERA
TION
Fig. 4.3: Normal Mode vs. Zero CAL-CHECK
®
Mode
SIGNAL
PROPORTIONAL
TO
FLOW RATE
MICROPROCESSOR
MASS FLOW
CALCULATION
NORMAL MEASUREMENT MODE
DDC-Sensor™
Outputs
Zero CAL-CHECK
™
MODE
Calibration
Validation
PASS/FAIL
MICROPROCESSOR
BASELINE RATE
COMPARISON
SIGNAL
AT
ZERO
FLOW RATE
DDC-Sensor™
Process Flow
“No Flow” Condition
Zero CAL-
CHECK
®
Operation: Zero CAL-CHECK
®
Achieving Zero Flow - Out of Pipe
If space limitations prevent in-situ testing at zero flow as listed above, then Out of Pipe
testing must be performed.
With this configuration, the meter must be removed from the process, the test
performed, and then the meter returned to the process after testing has been
completed.
Due to the high sensitivity of the DDC-Sensor™, it is necessary to isolate the sensor
once the meter has been removed from the pipe. This can be achieved with a closed
container in order to isolate the sensor and achieve the "no flow" condition necessary
to perform the Zero CAL-CHECK
®
test. If the Zero CAL-CHECK
®
test is to be
performed out of the pipe, the meter must be set upside-down (probe pointing up) and
a clean dry plastic bottle placed back over the sensor to achieve the factory baseline
that the meter has been set with.
Achieving
Zero Flow -
Out of Pipe
