Dwyer TFM-LP - Manual (Page 13)

F-20-TF-L, pg. 13 of 30
C. Operation
CAUTION : USE WITH LIQUIDS ONLY. FLOWING GAS OR AIR
THROUGH YOUR FLOW SENSOR WILL DAMAGE THE MICRO-
TURBINE ASSEMBLY. THIS TYPE OF DAMAGE WILL NOT BE
REPAIRED UNDER WARRANTY.
1.
Start Up
Before applying power to the unit check all tubing and electrical
connections. Once correct installation is verified switch on the power.
2. Entrapped Air or Gas
There may be a lot of air or gas trapped in your sensor after installation.
This will usually escape the unit when flow (within the range of the unit) is
first started.
CAUTION:
The system should be primed with liquid and flow
started gradually. This will prevent trapped air or gas from being
forced through the sensor at a high velocity that may damage the
sensor.
If gas remains entrapped in the unit it may be necessary to elevate the outlet
tubing above the inlet of the sensor. This should enable the trapped gas to
escape the unit. The sensor may be returned to its original position once all
the gas has escaped.
If elevating the outlet tubing does not work, block or pinch the outlet tube
whilst there is flow in the system. After approximately 5 seconds, release the
restriction to allow normal flow. Doing this will build up pressure in the flow
path that when released will help remove the entrapped gas. Repeat this
until the entrapped gas is removed from the unit.
3. Flow Readings
TFP-LP and TFM-LP Series sensors provide a 0-5VDC and pulse output
proportional to the flow rate.
The TFP-LI and TFM-LI Series feature an integral display that provides a local
flow reading and a 0-5VDC analog output.
Each flow sensor is factory calibrated for a specific flow range. The flow
range is shown on the unit’s label and calibration certificate. Units are
calibrated using deionized water as the reference media.