GMI Gasurveyor 500 Series, User Handbook Manual

Page: 23 / 102

2-5
GENERAL INFORMATION
Toxic Ranges
Two toxic ranges are possible on the Gasurveyor 500
series of instruments. The toxic ranges measure on the
ppm scale. The toxic sensors are subject to the effect of
pressure transients and should be operated at normal
atmospheric pressure conditions. The sensors have a
normal operating life of two years.
For the purposes of this manual the toxic ranges are
referred to as Toxic 1 and Toxic 2.
Alarms
The Gasurveyor 500, by default, has both audible and
visual alarms active when operating in Confined Space
Monitor Mode; see Confined Space Monitor (CSM)
Operation in Section 3. The audible alarm is rated up to 85
dB(A). The visual alarm is a red LED indicator which
protrudes from the instrument top plate, allowing viewing
from any angle above the top plate.
The instrument, by default, will have alarm levels for the
Flammable LEL, Oxygen, and Toxic gases pre-set.
The Gasurveyor 500 series has the facility to have two
(2) instantaneous alarm levels for each range in the
instrument. These are described as LOW and HIGH. By
default, only the high instantaneous is activated.
When both instantaneous alarms are set, the LOW audible
and visual alarm cycle will be activated for 0.5 seconds
on and 0.5 seconds off. The HIGH audible and visual
alarm cycle will be activated for 0.25 seconds on and
0.25 seconds off.
The option is to have all or some instantaneous alarms
deactivated.