Features - Teledyne HFM-301 Instruction Manual

301/303/305/306/307 Flowmeters and Controllers Instruction Manual

Features

LINEAR BY DESIGN. The HFM-301/305/306 and HFC-303/307 series are intrinsically linear (no linearization
circuitry is employed). Should field recalibration (a calibration standard is required) 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 overflows 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. Replacing the sensor requires a
recalibration.
FAST SETTLING TIME. Changes in flow rate are detected in less than 250 milliseconds when using the standard
factory PC board settings.
FIELD RANGEABLE. The Hastings 300 series is available in ranges from 0-5 sccm to 0-25 slm. Each flow meter
has a shunt which can be quickly and easily exchanged in the field to select different ranges. Calibration,
however, is required.
CURRENT LOOP. The 4-20 mA option gives the user the advantages of a current loop output to minimize
environmental noise pickup.
EAR99 Technology Subject to Restrictions Contained on the Cover Page Page 6 of 32