Heath Consultants Gasurveyor 500 Series - Manual (Page 15)

5
LEL Displayed as % Volume Equivalent
The LEL Displayed as a % Volume Equivalent is available
for methane in air calibrated instruments only.
In this mode, the range is displayed in the top right hand
corner of the display, as % Gas. From 0 to 100% LEL
Equivalent, the digital display resolves to 0.1% Gas.
Note: If you are using the Gasurveyor 3-500 instrument
for purge operations using the Volume Gas range, ensure
that LEL Displayed as a % Volume Equivalent range
option, is not selected as a user option.
Alarms
The Gasurveyor 3-500, by default, has both audible and
visual alarms off when operating.
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, where selected, can have alarm levels
for the Flammable LEL pre-set.
The Gasurveyor 3-500 has the facility to have two (2)
instantaneous alarm levels for the flammable LEL range
in the instrument. These are described as LOW and HIGH,
although generally only the high alarm would be active.
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.
GENERAL INFORMATION