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301/303/305/306/307 Flowmeters and Controllers Instruction Manual
Adjustments (Calibration Procedure)
The following section details adjustments that can be made to a
Hastings flow instrument's calibration. The process of making
these adjustments is only recommended if appropriate calibration
equipment is available, (appropriate leak-tight fittings and a valid
flow reference).
1.
Calibration must take place with cover firmly in place.
2.
Connect power to "D" connector as specified in Section
2.5. Allow the instrument to warm up for 60 minutes with
10% of full scale flow.
3.
Completely shut off the flow and wait for 2 minutes. Adjust
the zero pot located on the inlet side of the unit until it
indicates zero (0 V for voltage units or 4 mA for current
units). Turn on gas supply to inlet of instrument and adjust
the flow rate to the desired full scale flow as indicated by a reference flow meter/controller.
4.
Adjust Span pot until the indicated flow reads full scale (5.00 VDC or 20 mA). Perform this step
only if a calibrated reference flow meter is available.
5.
Record flow meter/controller and flow reference outputs for flow rates of 20%, 40%, 60%, 80%
and 100% and make sure data are within ± 1% of full scale.
Periodically, during normal operation, the ZERO should be checked and adjusted as needed. Refer to step
3 above.
Endcap Removal
The end cap on the inlet side must be removed to gain access to shunt assembly. First remove power
and shut off the supply of gas to the instrument. Disconnect the fittings on the inlet and outlet sides of
the transducer and remove it from the system plumbing. On the HFM-301/305 and HFC-303/307, Remove
the four screws holding the end cap to the instrument. Carefully remove the end cap, spring, and shunt,
noting their order and proper orientation. The shunt position and orientation is critical to the flow
dynamics and can substantially affect the instrument linearity. The shunt can be severely damaged if
dropped. Examine the shunt. If damaged, dirty or blocked, clean and replace as applicable.
Reassemble in the reverse order of disassembly. Use of a fastener other than the one mentioned here
may result in leakage at the seal. Recalibration of the Hastings 300 is necessary.
For the HFM-306, remove the six hex socket bolts from the inlet end cap. Note the order and orientation
of the internal parts. Remove the end cap and ensure that the o-ring is not damaged. Remove the flow
conditioning screen assembly and if damaged, dirty or blocked, clean and replace as applicable. Carefully
remove the flow straightener and shunt assembly. The shunt position and orientation is critical to the
flow dynamics and can substantially affect the instrument linearity. If damaged, dirty or blocked, clean
and replace as applicable. Reassemble in the reverse order of disassembly. Recalibration of the HFM-
306 instrument is necessary.
EAR99 Technology Subject to Restrictions Contained on the Cover Page
Page 24 of 32
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