Flowmeter SVTU-11B, Operating Manual

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the level of electromagnetic interference created by surrounding equipment, should
not exceed a permissible level for the meter.
Before hydraulic zero setting it is necessary to run the water meter in waterworks on the
maximal water flow rate for half an hour, then to cut off a valve after flow measurement sec-
tion, to cut off a valve before flow measurement section. Hydraulic zero setting can be con-
ducted in a few minutes after water fluctuations in the tapped section will stop.
If value of the first group of digits, displayed on the meter indicator and registered by
the meter as water zero velocity noticeably exceeds 500 or number of measurement cycles,
then some obstacles are possible on tapped FS:
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air bubbles in FS;
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water leak through valves;
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significant level of external electromagnetic noise.