RKI Instruments RM-5000 Series Indicator/Alarm Unit - Manual (Page 80)

11 Definition of Terms
- 80 - RM-5000
11
Definition of Terms
%LEL A percentage unit of the concentration of a combustible gas assuming the lower
explosive limit (LEL) of the combustible gas as 100. LEL (Lower Explosion Limit)
refers to the lowest concentration of a combustible gas in air capable of causing
explosion when ignited.
vol% Gas concentration indicated in the unit of one-hundredth of the volume
ppm Gas concentration indicated in the unit of one-millionth of the volume
Calibration Find relationship of the readings, display values or setpoints with the actual
values by using the calibration gas.
Maintenance mode When maintenance is performed on the indicator/alarm unit, the alarm contact is
disconnected, and a signal to indicate the maintenance mode status is sent out
to the external output signal. As a result, maintenance can be performed on a
single unit of the indicator/alarm unit.
Initial clear The reading is unstable for seconds after the power is turned on. To prevent
malfunctions for that period, the alarm contact is deactivated. In addition, a
signal to indicate the initial clear status is sent out to the external output.
Zero suppression A function to cut off the influences of environmental changes, interference
gases, etc.
Alarm delay time A function which temporarily suspends activation to prevent a false alarm
caused by noise from its outside.
Inhibit The gas detection function is temporarily suspended during maintenance, etc.
of the indicator/alarm unit. This is also called "point skip", which has the same
function.