Appendix D - Glossary - Honeywell Apex Technical Handbook

MAN0604_Issue 09_02-2013 Apex
2110M8030

APPENDIX D - GLOSSARY

Cartridge
.
A replaceable assembly containing a gas transducer and associated calibration information
Catalytic Bead
Used for the detection of combustible gases. These are made of an electrically heated platinum wire
coil, covered first with a ceramic base and then with a final outer coating of catalyst.
cE mark
Indicates compliance to all relevant European directives.
Electrochemical Sensor
A gas sensitive electrode, formed by a permeable membrane and special electrolyte.
Gas Transducer
An element that translates gas concentration into an electrically measurable quantity, such as
electrochemical cells, catalytic beads and thick film devices.
lcd
Liquid Crystal Display.
lEl
Lower Explosive Limit is the lowest concentration of fuel in air which will burn and for most
flammable gases and vapours it is less than 5% by volume.
Note: for some gases (e.g. methane) the LEL level has different values in the European and North
American standards.
lEl%
Percentage of the Lower Explosive Limit (for example, 10% LEL of methane is approximately 0.5%
by volume).
lOn
Local Operating Network.
pcB
Printed circuit board.
peak
Maximum, or minimum, measurement since switch on.
ppB
Parts per billion concentrations in the atmosphere.
ppm
Parts per million concentrations in the atmosphere.
rh
Relative humidity.
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