Can Kytola Flow Meters Measure Different Media or Operate Under Conditions Different from Their Nameplate Ratings?

Author: WeidoyaPublished: 2026-01-14 14:27:45Views: 0

The flow meter displays the correct reading only when operating conditions match the design values marked on its scale.

A conversion factor is required for other operating conditions.

Gas flow meter calculation formula.

Q₀ = Actual flow rate

ρ₀ = Specific gravity of measured gas (Air = 1)

p₀ = Actual ABSOLUTE pressure in metering tube

T₀ = Actual ABSOLUTE temperature
(Kelvin) in metering tube

(0°C = 273,15°K)
(20° C = 293,15°K)

Q₁ = Flow meter reading

ρ₁ = Specific gravity of design gas (Air = 1)

p₁ = ABSOLUTE design pressure
(calibration pressure)

T₁ = ABSOLUTE design temperature
(Calibration temperature)

Example 1

What is the maximum flow if flow meter EK-3NR is used for carbon dioxide at 3 bar(g) / 25°C.

Ex-3NR scale is

Q₁ = 12 NL/min
ρ₁ = 1
p₁ = (0+1,013) bar = 1,013 bar
T₁ = 293,15°K

Q₀ = ?
ρ₀ = 1,529
p₀ = (3+1,013) bar = 4,013 bar
T₀ = 298,15°K

Actual flow at 12 NL/min reading
Q₀ = 19,15 NL/min CO2 at 3 bar(g)/ 25°C

Flow meter LH-JJ32 is calibrated for 30 NL/min nitrogen at 3 bar(g)/ 20°C

What is the actual flow if flow meter LH-JJ32 is used for helium at 5 bar(g) / 10°C.

Q₁ = 30 NL/min
ρ₁ = 0,9672
p₁ = (3+1,013) bar = 4,013 bar
T₁ = 293,15°K

Q₀ = ?
ρ₀ = 0,1380
p₀ = (5+1,013) bar = 6,013 bar
T₀= 283,15°K

Actual flow at 30 NL/min reading
Q₀ = 98,9 NL/min He at 5 bar(g)/ 10°C

Related Tags: