Teledyne 202 Manuale Utente

 

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The Hastings HFM-200 mass flow meter and HFC-202 flow controller  are  designed to accurately 

measure and control mass flow over the range of 10 sccm to 30 slm, without corrections or 
compensations for gas pressure and temperature with an accuracy of better than ±1% FS.  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.  

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LINEAR BY DESIGN.  The HFM-200/HFC-202 series is inherently linear (no linearization 
circuitry is employed).  Should recalibration in the field be desired (a calibration standard is 

required), 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. 

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MODULAR SENSOR.  The HFM-200/HFC-202 series incorporates a removable/replaceable 
sensor module.  Field repairs to units can be achieved with a minimum of production line downtime.  

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METER SETTLING TIME.  Changes in flow rate for the HFM-200 are detected in less than 2 
seconds when using the fast-response circuitry. 

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LOW TEMPERATURE DRIFT.  The temperature coefficient of span for the HFM-200/HFC-

202 series is typically less than 0.05% of full scale/°C from 15-45°C.  The temperature coefficient of 
zero is typically less than 0.1 % of reading/°C from 0-50°C. 

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CURRENT LOOP.  The 4-20 mA option gives the user the advantages of a current loop output to 
minimize environmental noise pickup.