XDT User’s Manual |
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| used for the circuit (see 4/20) |
dB | see - decibel |
DB25 | a style and size of connector - in this case with 25 pins |
DB9 | a style and size of connector - in this case with 9 pins |
decibel | a dimensionless unit representing the logarithm of the ratio of two |
| values |
DEMKO | independent test laboratory and the European National Certification |
| Body for Denmark for the safety testing of electrical products |
desiccant | drying agent, usually made from molecular sieve, silica gel or acti- |
| vated alumina |
desorption | release of a previously absorbed or adsorbed substance |
dewpoint | saturation temperature of a gas in regards to another gas |
dewpoint demand mode . . . . | scheme to control the switching between the desiccant towers of a |
| dryer based on the actual dewpoint |
dielectric constant | measure of the ability of a material to hold an electric charge when |
| placed between two metal plates, most commonly measured rela- |
| tive to that of free space |
Div 2 | see Division 2 Hazardous Areas |
Division 2 |
|
Hazardous Areas | areas classified as hazardous under abnormal conditions |
| hrs/year) |
DSR | Data Set Ready - a label for a RS232 interface control line |
DTR | Data Terminal Ready - a label for a RS232 control line |
EEPROM | Electrically Erasable Programmable Read Only Memory - a device |
| that can remember information, even when it has no power applied |
| to it |
electromagnetic
compatibility . . . . . . . . . . compatibility with directives issued under CE or with FCC stan- dards, concerning electromagnetic interference
EMI . . . . . . . . . . . . . . . . . . . .
G/M3 . . . . . . . . . . . . . . . . . . . see - grams per cubic meter
grams per cubic meter . . . . . . the mass of water vapor present in unit volume of moist air at stan- dard temperature and pressure.
HTF™ . . . . . . . . . . . . . . . . .
hygrometer . . . . . . . . . . . . . . device measuring the amount of water present in a sample hygroscopic . . . . . . . . . . . . . . property of attracting water or water vapor
hysteresis. . . . . . . . . . . . . . . . lagging in effect behind it’s cause depending upon whether the con- dition is approached from above or below the value of interest; pur- 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
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