COSA Xentaur Xentaur XDT - Manual (Page 40)

Glossary
33
posefully programmed into control systems with relays to avoid
chatter
IGT Research Bulletin 8 . . . . Institute of Gas Technology, has developed Charts of the Equilib-
rium Moisture Content of Natural Gases in the Range of -40°F to
250°F and 14.7 to 5000 psi
impedance . . . . . . . . . . . . . . . the ratio of voltage to current at a specified frequency measured in
Ohms, a resistor of the same value would act the same as the mea-
sured circuit
in-hand micro-climate. . . . . . the warm and moist “climate” created when cupping the sensor in
ones hand.
in-situ . . . . . . . . . . . . . . . . . . measurement with sensor located in the process stream
intrinsically safe . . . . . . . . . . incapable of releasing enough electrical or thermal energy to cause
the ignition of flammable substances listed for a hazardous area
classification
LBS H
2
O/mmscf. . . . . . . . . . see - pounds of water per million standard cubic feet
LCD . . . . . . . . . . . . . . . . . . . Liquid Crystal Display - a display that uses a special material (that
is sensitive to electrical voltages) to affect the transmission or
reflection of light
monograph . . . . . . . . . . . . . . a systematic learned exposition of a subject, e.g. a chart represent-
ing dewpoint conversions for differing pressures.
National Electrical Code . . . . a set of US standards related to accepted practices for electrical wir-
ing
NFPA. . . . . . . . . . . . . . . . . . . National Fire Protection Agency (issuer of the National Electrical
Code (NEC))
NIST . . . . . . . . . . . . . . . . . . . National Institute of Standards and Technology
NPT . . . . . . . . . . . . . . . . . . . . National (American Standard) Pipe Taper; an ASTM (American
Society for Testing and Materials) standard of tube fittings with
tapered threads
parity . . . . . . . . . . . . . . . . . . . a way of incorporating error checking into a RS232 data transmis-
sion (on a character by character basis) to check if the data has been
received correctly
pounds of water per
million standard cubic feet . (LBS H
2
O/mmscf) the mass of water vapor present in unit volume
of moist air at standard temperature and pressure.
a measurement unit for moisture, typically used in the natural gas
industry
ppm . . . . . . . . . . . . . . . . . . . . parts per million - usually based on volume measure, but must be
stated whether it is by volume or by mass (weight)
ppmV . . . . . . . . . . . . . . . . . . parts per million based on volume measure, volume of water vapor
per total volume of gas for an ideal gas.
pressure correction . . . . . . . . computation of dewpoint at a pressure different from the pressure at
the sensor
PROM . . . . . . . . . . . . . . . . . . Programmable Read Only Memory - a device that can be pro-
grammed so that data is permanently stored in it (typically used for
computer programs)
RAM . . . . . . . . . . . . . . . . . . . Random Access Memory - a device that holds data as long as it has