11. Appendix 11-2. Terminology
- 151 -
11-2. Terminology
ppm Indicates gas concentration in units of parts per million by volume.
% Indicates gas concentration in units of parts per hundred by volume.
Calibration
Determining correlation between product readout values, display values, and setting values
with actual values using calibration gas
Cumulative value
This is the time-weighted average for one hour.
The duration for which the gas has been present is multiplied by the carbon monoxide
concentration value. After the sum of this result (value) is calculated, it is divided by the
number of hours to provide the exposure amount per hour.
TWA
Acronym for Threshold Limit Value Time Weighted Average
Time-weighted average concentrations of a harmful substance considered to have no
adverse health effects in nearly all workers, even with repeated exposure, during normal
work for 8 hours per day or 40 hours per week
STEL
Acronym for Threshold Limit Value Short Term Exposure Limit
Concentrations of a harmful substance considered to have no adverse health effects in
workers, even with continuous exposure for 15 minutes, provided daily exposure does not
exceed the TWA
Self-latching
Configuration in which an alarm persists, once triggered, unless reset, even when alarm
conditions no longer apply
Auto reset
Configuration in which an alarm stops automatically after being triggered when alarm
conditions no longer apply
To Next Page
Loading...
Need help?
General
