2
GENERAL
The Instromet IRM Infinity rotary piston gas meter is a positive displacement type meter which, by means of a counter,
registers the quantity of gas in units of volume at the prevailing measurement pressure and temperature (operating m
3
).
The Instromet rotary meter fully complies with the requirements of many international and national standards regar-
ding design and accuracy and is approved to EEC and Dutch specifications by the Nederlands Meetinstituut (NMI). Instro-
met BV is certified in accordance with ISO 9001.
THE IRM INFINITY ROTARY PISTON GAS METER
Stress-free and low-noise replaceable meas-
urement module embedded in flexible seals.
Temperature sensor points
Oil filling
(under index)
Hinged type plate
Oil drain
Low frequency
connections
Oil sight gauge
Pressure Point
Pressure Point
OPERATION
The Instromet IRM Infinity meter is a high accuracy positive displacement meter
which is insensitive to changes in the relative density of the gas to be measured.
Measurement takes place by means of two figure eight rotors (synchronized by
gears) which rotate in a chamber of known volume. Four times per revolution, a
fixed unit of volume is displaced (see hatched area in drawing). Therevolutions of
the rotors are transmitted to the counter by means of a magnetic coupling. The
design, combined with the precision-finishing of both the rotors and the measu-
ring chamber, ensures a
continuous seal without
actual contact between
these
components.
This
minimizes the possibility of
gas passing through the
chamber without being
measured.
Main-measurement chamber and rotors
The Instromet IRM Infinity meter is
suitable for the measurement of all
non-corrosive gases, such as natural
gas, propane, butane, air, nitrogen,
dry hydrogen, ethylene, etc. The IRM
Infinity meter can be used for meas-
urement where a high accuracy is
required over a wide operating range
APPLICATIONS
