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PTFM 1.0 Portable Transit Time Flow Meter
SENSOR COUPLING
For permanent or temporary bonding, the following are recommended:
a)
Dow Corning silicon compound #4 (supplied)
Additional supply: order Greyline Option CC
b)
Water-based sonic compound: Order Greyline Option CC30
c)
Electrocardiograph gel
d)
Petroleum gel (Vaseline)
The above are arranged in their order of preferred application.
d is only good for temporary bonding at room temperature.
DO NOT USE: Silicon RTV caulking compound (silicon rubber).
Use the pipe clamp and rail (supplied) as illustrated on previous page or use
a loop of electrical tape for temporary mounting. Apply silicon coupling
compound #4 to the colored face of the sensor. A bead, similar to toothpaste
on a toothbrush, is ideal. Do not overtighten (crush the sensor).
The sensor must be fixed securely to the pipe with coupling material
between the sensor face and the pipe. Sensor installation with
excessive coupling compound can result in gaps or voids in the
coupling and cause errors or loss of signal. Insufficient coupling
compound will create similar conditions.
Over time temporary coupling compounds (e.g. Petroleum Gel) may gradually sag away from the sensor
resulting in reduced signal strength and finally complete loss of signal. Warm temperatures, moisture
and vibration will accelerate this process. Dow Corning Silicone Compound #4 as supplied with the
PTFM 1.0 (and available from Greyline Instruments) is recommended for semi-permanent installations.
