Spirax Sarco RIM20, Installation And Maintenance Instructions Manual, Page: 131 / 132

IM-P198-05 MI Issue 2 131
Q
Q Flowrate, usually volumetric.
R
Rangeability
Highest measurable flowrate divided by the lowest measurable
flowrate.
Reynolds number
A dimensionless number equal to the density of a fluid or Retimes
the velocity of the fluid times the diameter of the fluid channel,
divided by the fluid viscosity (i.e., Re = r VD/ m ). The Reynolds
number is an important num- ber for turbine flowmeters because
it is used to determine the minimum measurable flowrate. It is the
ratio of the inertial forces to the viscous forces in a flowing fluid.
Rotor
The velocity sensing element of a turbine flowmeter.
Rotors are manufactured with the blades at a certain pitch. The
pitch of the rotor blades determine the maximum velocity the
turbine flowmeter can be used in.
RTD
Resistance temperature detector, a sensor whose resistance
increases as the temperature rises.
S
scfm
Standard cubic feet per minute (flowrate converted to standard
conditions, usually 14.696 psi a and 682 F).
T
Totalizer
An electronic counter which records the total accumulated flow
over a certain range of time.
Traverse
The act of moving a measuring point across the width of a flow
channel.
U
Uncertainty
The closeness of agreement between the result of a measurement
and the true value of the measurement.
V
V Velocity or voltage.
Vac Volts, alternating current.
Vdc Volts, direct current.