Teledyne HASTINGS 200 Series, Instruction Manual, Page: 8 / 28

126B - PAGE 8
The standard inlet and outlet fittings for the HFM-229B Flowmeter are NPT thread in the size of the
pipe listed on the drawing on page 22, for sizes up to 3" laminar. On the 4", 6", and 8" laminars, flange
fittings are standard. Smooth tubulation is optional on all sizes.
It is suggested that all connections be checked for leaks after installation. This can be done by pressuriz-
ing the transducer (do not exceed 500 psig unless the transducer is specifically rated for higher pres-
sures) and applying a diluted soap solution to the flow connections.
2.5 Electrical Connections: 2.5 Electrical Connections: 2.5 Electrical Connections: 2.5 Electrical Connections: 2.5 Electrical Connections:
If a power supply was purchased from Hastings Instruments, installation will consist of connecting the
cable, purchased separately from the power supply, from the rear of the supply to the top of the
flowmeter. If a Hastings supply was not purchased, follow the instructions below to connect up the
flowmeter.
The power supply used must be capable of supplying ±15VDC at ±50mA . These voltages must be
referenced to a common ground.
Refer to Fig. 2.1. Connect -15VDC to pin 9 and +15VDC to pin 11. Pin 5 is common and must be
connected to the common connection at the power supply. Pin 7 is the case ground and it should be
connected to the cable shield if available, and to AC ground of the power supply. Pin 6 is the output
signal from the flowmeter. This output will be 0-5VDC, 5VDC being 100% of rated or full flow.
2.6 Operation: 2.6 Operation: 2.6 Operation: 2.6 Operation: 2.6 Operation:
2.6.1 P 2.6.1 P
2.6.1 P 2.6.1 P
2.6.1 Pooooow w
w w
wer Supply Opera er Supply Opera
er Supply Opera er Supply Opera
er Supply Operation tion
tion tion
tion
Do not connect transducers while the power supply is energized. The display may read either percent of
full scale or actual flow rate, depending on the power supply purchased. To read flow rate, turn display
switch to desired channel.
2.6.2 2.6.2 2.6.2 2.6.2 2.6.2 Ambient Ambient Ambient Ambient Ambient T T T T Tempera empera empera empera emperature ture ture ture ture
In order to maintain the accuracy of the flowmeter with changes in ambient temperature, it is necessary
to keep the temperature of the transducer between 0
o
C and 50
o
C. Since some of the temperature shift
results in a slight zero offset, better results are obtained if the flowmeter is re-zeroed at the operating
temperature. The flowmeter calibration may change by a factor up to 0.1%/
o
C. Hastings Mass
Flowmeters are for GAS flow, so DO NOT let the temperature and/or pressure of the gas
reach a point that would cause the gas to change to a liquid state, or erroneous indications will result.
2.6.3 Zero Check 2.6.3 Zero Check
2.6.3 Zero Check 2.6.3 Zero Check 2.6.3 Zero Check
Turn the power supply “ON”. Allow the flowmeter 10 minutes to warm up. Stop all flow through the
transducer and check electrical zero.
CAUTION: Do not assume that all metering valves will completely shut off flow. Even a slight leakage
through a valve will cause an indication on the meter which will falsely appear to be a zero shift.
If necessary, adjust the “ZERO” potentiometer, located on the lower inlet side of the transducer, until
the meter indicates zero. This zero should be checked periodically during normal operation.
2.7 Range Changing: 2.7 Range Changing:
2.7 Range Changing: 2.7 Range Changing: 2.7 Range Changing:
The range of the flowmeter can be changed in the field if recalibration facilities are available. The
instructions to change the flow range can be found in Section 4.5. In order to change the range of a
Model HFM-230 Flowmeter, a new laminar flow element must be purchased from the factory.