General Information; Features - Teledyne HASTINGS HFM-300 Instruction Manual

1. General Information

The Teledyne Hastings HFM-300 is used to measure mass flow rates in gases. In addition to flow rate
measurement, the HFC-302 includes a proportional valve to accurately control gas flow. The Hastings
mass flow meter (HFM-300) and controller (HFC-302), hereafter referred to as the Hastings 300
series, are intrinsically linear and are designed to accurately measure and control mass flow over the
range of 0-5 sccm to 0-10 slm with an accuracy of better than ±0.75% F.S. at 3σ from the mean
(versions >10 slm are ±1.0% F.S.) . Hastings mass flow instruments do not require any periodic
maintenance under normal operating conditions with clean gases. No damage will occur from the
use of moderate overpressures (~500 psi/3.45MPa) or overflows. Instruments are normally calibrated
with the appropriate standard calibration gas (nitrogen) then a correction factor is used to adjust
the output for the intended gas. Calibrations for other gases, such as oxygen, helium and argon, are
available upon special order.

1.1. Features


LINEAR BY DESIGN. The Hastings 300 series is intrinsically linear (no linearization circuitry is
employed). Should recalibration (a calibration standard is required) in the field be desired, the
customer needs to simply set the zero and span points. There will be no appreciable linearity change
of the instrument when the flowing gas is changed.

NO FOLDOVER. The output signal is linear for very large over flows and is monotonically increasing
thereafter. The output signal will not come back on scale when flows an order of magnitude over the
full scale flow rate are measured. This means no false acceptable readings during leak testing.

MODULAR SENSOR. The Hastings 300 series incorporates a removable/replaceable sensor module.
Field repairs to units can be achieved with a minimum of production line downtime.

LARGE DIAMETER SENSOR TUBE. The Hastings 300 sensor is less likely to be clogged due to its large
internal diameter (0.026"/ 0.66mm). Clogging is the most common cause of failure in the industry.

LOW P. The Hastings 300 sensor requires a pressure of approximately 0.25 inches of water (62 Pa) at
a flow rate of 10 sccm. The low pressure drop across this instrument is ideal for leak detection
applications since the pneumatic settling times are proportional to the differential pressure.

FAST SETTLING TIME. Changes in flow rate are detected in less than 250 milliseconds when using the
standard factory PC board settings.

LOW TEMPERATURE DRIFT. The temperature coefficient of span for the HFM-301/HFC-303 series is
less than 0.08% of full scale/°C from -20-70°C. The temperature coefficient of zero is less than 0.12%
of reading/°C from -20-70°C.

FIELD RANGEABLE. The Hastings 300 series is available in ranges from 0-5 sccm to 0-25 slpm. Each
flow meter has a shunt which can be quickly and easily exchanged in the field to select different
ranges. Calibration, however, is required.

METAL SEALS. The Hastings 300 series is constructed of Stainless Steel. All internal seals are made
with Ni 200 gaskets, eliminating the permeation, degradation and outgassing problems of elastomer O-
rings.

LOW SURFACE AREA. The shunt is designed to have minimal wetted surface area and no un-swept
volumes. This will minimize particle generation, trapping and retention.

CURRENT LOOP. The 4-20 mA option gives the user the advantages of a current loop output to
minimize environmental noise pickup.
Manual: 151-032015 300-302 Series
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