Application Information
Page 12
April 2017
VAM-UM-00646-EN-04
APPLICATION INFORMATION
Liquid
Viscosity Effect (SUS/cSt)
The design uses a precision machined, sharp-edged orifice and biasing calibration spring
that assures operating stability and accuracy over the wide viscosity range, common
to many fluids High flow models of each flow meter size provide good accuracy over a
viscosity range of 40…500 SUS (42…109 cSt)
Density Effect
(specific gravity)
Any fluid density change from stated standards has a proportional effect on flow meter
accuracy Special scales can be supplied if actual specific gravity decreases accuracy beyond
application limits Corrections for more or less dense fluids can be made to standard scales
using the following correction factor:
1 0
.
Specific Gravity
for water/water-based flow meters
0 876
.
Specific Gravity
for petroleum-based flow meters
Pneumatic
OTE:
N
Pressure and temperature readings must be taken at the flow meter inlet to provide accurate
correction factors
The pneumatic flow meter is offered with a standard graduated dual scale, calibrated for air
in standard cubic feet per minute (scfm) at 10 sg (70° F @ 100 psi) and liter per second (lps)
at 10 sg (21° C @ 69 bar)
PRESSURE
SOURCE
FLOW
METER
AIR BLEED OFF
TO EQUIPMENT
ADJUSTABLE
VALVE
PRESSURE
GAUGE
TEMP
Figure 10: Pneumatic flow meter
