HFM-401/405 - Teledyne Hastings Instruments
HFM-401/405 - Teledyne Hastings Instruments
HFM-401/405 - Teledyne Hastings Instruments
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
250%Flow meter OutputIndicated Flow (% Full Scale)200%150%100%50%Analog OutputDigital Output0%0% 100% 200% 300% 400% 500% 600%Flow (% Full Scale)3.4.2.3.6. Reverse FlowIf the flow through the flowmeter reverses and flowbegins to enter the exit of theflow meter and leave throughthe entrance of the flow meterthe flow meter will measurethis flow and report it digitallywith reduced accuracy. Theanalog output will alsoindicate this by eithergenerating a negative outputvoltage or decreases thecurrent output below 4 mA,depending on whether avoltage or current output hasbeen selected.3.7. High PressureOperationWhen operating at highpressure, the meter’sperformance can be affectedin two distinct and separateways—a zero shift and a span(calibration) shift.Span Shift (% Reading)Pressure Effect876543210-10 200 400 600 800 1000Line Pressure (psig)Figure 3-1 The pressure effect on flow calibration (for nitrogen)<strong>401</strong>-<strong>405</strong> SERIES - 18 -