ABB Totalflow NGC8206 Manuel D'utilisation page 262

Demand Load
Demand Meters
Demand, Average
Density
Desaturization
Detector Bead
Deviation
Dew Point
Dewar
DG
Diaphragm
Differential
Differential Input
Differential Pressure
Digit
Digital
Page B–18
The rate of flow of gas required by a consumer or a group of
consumers, often an average over a specified short time interval (cf/hr
or Mcf/hr). Demand is the cause; load is the effect.
A device which indicates or records the instantaneous, maximum or
integrated (over a specified period) demand.
The demand on a system or any of its parts over an interval of time,
determined by dividing the total volume in therms by the number of
units of time in the interval.
Mass per unit Volume: D=MV
Doesn't cause the composition of the gas to change, enabling a more
representative sample of gas.
See Thermal Conductivity Detector.
The difference between the value of the controlled variable and the
value at which it is being controlled.
The temperature at any given pressure at which liquid initially
condenses from a gas or vapor. It is specifically applied to the
temperature at which water vapor starts to condense from a gas
mixture (water dew point) or at which hydrocarbons start to condense
(hydrocarbon dew point).
A glass or metal container made like a vacuum bottle that is used
especially for storing liquefied gases. Also called "Dewar flask".
Display Group. When display group files are created
A bellows inside a displacement type gas meter. Also, a membrane
separating two different pressure areas within a control valve or
regulator.
For an on/off controller, it refers to the temperature difference between
the temperature at which the controller turns heat off and the
temperature at which the heat is turned back on. It is expressed in
degrees.
A signal-input circuit where SIG LO and SIG HI are electrically floating
with respect to ANALOG GND (METER GND, which is normally tied to
DIG GND). This allows the measurement of the voltage difference
between two signals tied to the same ground and provides superior
common-mode noise rejection.
The pressure difference between two points in a system. For example,
the difference in pressure between the upstream and downstream taps
of an orifice plate, used to measure volume passing through the orifice.
A measure of the display span of a panel meter. By convention, a full
digit can assume any value from 0 through 9, a 1/2-digit will display a 1
and overload at 2, a 3/4-digit will display digits up to 3 and overload at
4, etc. For example, a meter with a display span of ±3999 counts is said
to be a 3-3/4 digit meter.
A signal which has distinct states, either on or off (0 or 1). Digital
computers process data as binary information having either true of false
states.
2103971-001 – rev. AB