Terminology - MSA Chillgard RT Instruction Manual

Terminology

Become familiar with the following terminology.
ZERO- A zero (0) indication on the meter display usually indicates fresh
air (no refrigerant gas present).
ZEROING- The process of placing a zero gas on the unit during
calibration.
SPAN- Full-scale or up-scale reading on meter display.
SPANNING- The process of placing a full-scale or span gas on the unit
during calibration.
SPAN GAS VALUE- The gas concentration that gives the instrument a
full-scale or up-scale value. This value is printed on the calibration gas
cylinder containing the gas.
FLOW RATE- Volume of gas drawn through the sample line per minute.
EXHAUST GAS- Sample gas after it passes through the sensor.
PUMP- The electric motor driven device that moves the gas sample to
the Chillgard RT Monitor.
ALARMS- The Chillgard RT System has three alarms to alert the user
at specific, user-adjustable refrigerant gas concentrations.
(Level 1 = Caution, Level 2 = Warning and Level 3 = Alarm.)
RELATIVE HUMIDITY- The percent of water vapor saturation in air at a
given temperature.
POINT NUMBER- The location or area from which a gas sample is
drawn. Up to four or eight areas, sequentially numbered from 1 to 8,
can be sampled.
BYPASS- The Sequencer is a look-ahead system; bypass gas flow is
drawn from the next area to be sampled. This feature reduces the
monitor response time when long sampling lines are used.
FRESH AIR- Air that has no possibility of containing refrigerant gas.
TEMPERATURE EFFECT- The gas response displayed by the
instrument (PPM) can change +0.3% for each degree (C) that the
instrument is operating above/below the temperature at which the
instrument was last calibrated.
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