ADS Environmental Services PrimeLog QR 775015 A0 - Manual (Page 23)

ADS PrimeLog User Manual
19
Quadrina Insertion Meters
Quadrina insertion meters are probes that are inserted, usually on a temporary
basis, into mains supply pipes and measure velocity.
The Quadrina Range
ADS supplies these probes in two sizes, standard (Probeflo) and miniature
(Miniprobe), and both are equipped for unidirectional or bi-directional flow.
While two options of the insertion tube are available, eight hardware
variations exist. Each variation may be equipped with an MEP or QEP
electronic interface.
The QEP interface requires no power from the logger and, therefore, is
compatible with all PrimeLog instruments. Its pulse frequency is linear
against velocity.
The MEP interface normally requires power from the logger. The PrimeLog
submersible range requires the use of an Auxiliary Battery Unit. The MEP
output pulse frequency is non-linear.
An internal-powered MEP interface allows for a direct interface with the
PrimeLogs without auxiliary batteries.
Volumetric Flow Measurement
Flow volume must be calculated based on the velocity measurement taken at
one point in the flow. In general, this point corresponds to the centerline of
the pipe because flow typically occurs symmetrically about this point.
The probe creates an obstruction in the flow (blockage factor). Therefore,
ADS supplies F-factor tables that provide the ratio of mean velocity to
(measured) centerline velocity. These factors compensate for the obstruction
that occurs from the probe in common pipe sizes.
Probe Calibration
Each probe comes with a calibration certificate indicating the number of
pulses produced per meter of flow. In other words, it is the number of pulses
produced per second for each meter per second of flow rate.
Probes fitted with QEP interfaces have single-point calibration. For the non-
linear MEP interfaces, calibration values are supplied for several different