Technology document

The flow meter will produce by order based on the condition used.
In the case of an estimate, please direct the measured fluid name, range of flowing quantity, pressure, temperature,etc.

It is necessary for measuring liquid (specific gravity and viscosity).

When the liquid of the water corresponding is measured, it is of no matter, but we be designed and product with specific gravity and viscosity. A temperature variation is a big influence is exerted on the display of flowing quantity, so please keep a fixed temperature as much as possible.

It is necessary for measuring gas (pressure and temperature).

we will set the condition of the measured gas (pressure and temperature) and produce
the flow meter for the gas.
The flow quantity becomes flow quantity converted into normal condition (atmospheric pressure 20 degrees Celsius).
In addition, we produce even a standard state (atmospheric pressure 0 degrees
Celsius) by a demand.

Fig. A, pressure 0.3MPa joins the needle valve and figure A becomes a state (atmospheric pressure) without pressure drag after it.Setting pressure is atmospheric pressure (1atm).

Fig. B, Pressure 0.3MPa joins the flow meter and the needle valve, and even when be that the atmospheric pressure or some load pressures joins after that, set pressure becomes 0.3MPa.

Please always do setting pressure in the state that constant pressure hung over to a flowmeter by pressure when gas to measure passes by in a flowmeter.In addition, when pressure and the temperature change, it will correct it by the value of fluctuations.


The principle of accuracy is within based on JIS ±2%- ±5% of maximum scale value (F.S). However, accuracy might decrease when it is the following.

  • Minute flow quantity
  • Liquid of high viscosity
  • Gas with extremely small density

Withstand pressure/ leakage inspection

It does by the pressure 1.5 times the maximum use pressure.

Flow correction formula

Liquid correction formula

When the density is different in the different kind liquid


Different kind gas, Pressure and temperature correction formula

When the unit of pressure is kPa
When the unit of pressure is kgf/cm2(G)

Steam correction formula

  *In general, the steam shows Mass(weight) by the unit

Explanation of sign

Q True flow quantity
q Flow quantity on a dial
ρf Density of a float
ρ0 Density of a fluid on a dial
ρ1 Density of a different fluid
P0 Pressure (kPa/kgf/cm2G) on a dial
P1 Different pressure (kPa/kgf/cm2G)
T0 Temperature on a dial
T1 Different temperature
W1 True flow quantity (mass)
W0 Flow quantity (mass) on a dial
γ0 Density of steam on a dial
γ1 Density of different steam
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