Teledyne hfc-302 ユーザーズマニュアル

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Manual: 151-082010 300-302 Series
  
Page 4 of 31 
 
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 Hastings 300 series is less 
than 0.03% of full scale/°C from 15-50°C.  The temperature coefficient of zero is less than 0.1 % of 
reading/°C from 0-60°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.