Glossary
Glossary
0/24 mA . . . . . . . . . . . . . . . . range of current for the current loop (0mA=minimum reading, 24mA=maximum reading)
4/20 mA . . . . . . . . . . . . . . . . range of current for the current loop (4mA=minimum reading, 20mA=maximum reading) - preferred because less than 4mA can indicate a fault or open circuit, also there is at least 4mA available to power equipment
7 segment . . . . . . . . . . . . . . . type of display configuration - where 7 segments can be used to form the numbers 0 through 9 and most letters
A/D . . . . . . . . . . . . . . . . . . . . analog to digital - a device or circuit that converts an analog voltage to a digital number
absorption . . . . . . . . . . . . . . . retention by penetration into bulk of material adsorption . . . . . . . . . . . . . . . retention as a surface layer on a material
accuracy . . . . . . . . . . . . . . . . quantification of the magnitude of error of a measurement, or degree of conformity with a standard.
Al2O3 . . . . . . . . . . . . . . . . . . aluminum oxide
attenuation | the decrease in intensity of a signal, as a result of absorption of |
| energy, measured in decibels (dB). |
AWG | American Wire Gauge (size of the wire, cross section area of the |
| wire) |
baud | Bits per second of data transfer (over the serial interface) |
bit(s) | Binary digit(s) - ones and zeros |
BNC | a connector type, used with coaxial cables |
bypass mounting | sensor mounting in a slip stream of sample, which feeds back into |
| the process stream |
CE | Conformitée Europeane; symbol affixed to a product indicating its |
| conformance with directives issued by the European Community |
| (EC) |
CENELEC | Comité Europeen de Normalisation Electrotechnique (European |
| Committee for Electrotechnical Standardization); amongst many |
| others has set standards for intrinsic safety |
check sum | an arithmetic total on a set of data: e.g. the data in the instrument's |
| memory is summed, and compared to a previously stored sum to |
| check for corrupted data |
coalescing | formation of liquids in gas samples, or separation and collection for |
| disposal of liquids from gas samples |
control drawing | schematics and system drawing of hazardous area approved appara- |
| tus with control number issued by approval agency |
CSA | Canadian Standards Association |
CTS | Clear To Send - a label for a RS232 interface control line |
cUL | indicates UL evaluation of a product to Canadian safety require- |
| ments |
current loop | a circuit where the variation in the current flow is used to indicate |
| the value of a measurement from the instrument, only 2 wires are |
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