Meriam Laminar Flow Elements User Manual

1 User’s Manual Laminar Flow Elements 10920 Madison Avenue Cleveland, Ohio 44102▪Tel: 216.281.1100▪email:[email protected]▪Web:www.m

10 Actual Volumetric Flow Rate 1) To obtain actual volumetric flow rate at inlet flowing temperature other than 70ºF, find the flow rate

11 Actual Volumetric Flow Rate 1) To obtain actual volumetric flow rate if the inlet temperature is different from standard temperature, read th

12 Table A-31031 Meriam Laminar Flow Element Pressure Correction Factor (any Gas) Base Pressure (Assigned Standard) 29.92 Inches Mercury Absolute LA

13 Table A-31986 Air Viscosity Correction Factors for ACFM Base Viscosity 181.87 Micropoise at 70°F Correction Factor =  Note: These

14 Table A-32422 A i r T e m p e r a t u r e / V i s c o s i t y C o r r e c t i o n F a c t o r s f o r S C F M A i r B a s e T e m p

15 Temp °F +0 +1 +2 +3 +4 +5 +6 +7 +8 +9 50 60 70 80 90 100 110 120 130 140 150 1.0392 1.0192 1.0000 0.9815 0.9636

16 When you decide to have your LFE cleaned, please be aware of the various capabilities of calibrating LFE’s at Meriam. Every calibr

17 LFE Dimensions

2 TABLE OF CONTENTS Subject Page Introduction ...

3 Introduction Because of their inherently high accuracy, stable calibration, excellent response time and repeatability, Laminar Flow Ele

4 Operation Establish flow through the LFE. Measure the differential pressure between high pressure sensing port and low pressure sensing p

5 Calibration Curve Table Meriam performs an air calibration of the LFE using a master flowmeter that is traceable to the National Standards and

6 To help calculate the viscosity of air at flowing temperature, a viscosity equation based on temperature is included in this instruction manual (se

7 Be sure to use the same absolute units for pressure (i.e. PSIA, mm Hg absolute,...) and temperature (ºK or ºR). The result is the s

8 Table A-35600 (NBSIR 83-2652) Humidity Correction Factor for Air = Pwet / Pdry % Relative Humidity °F 20% 40% 60% 80% 100% 40 .9993

9 Determining Flow from your Laminar Flow Element Calibration Curve/Table The curve/table of each LFE is normalized to standard conditions lis