beautypg.com

ENMET ISA-44-2OD User Manual

Page 12

background image

ENMET Corporation

ISA-44-2-OD

8

3.2 Sensor Location

Gases have different densities. Some are heavier than air and concentrate at the bottom of a space. Some are lighter
than air and gather at the top. Consider the density of the gas you want the sensor to detect when you install the
sensor. As a guide, consult the gas descriptions below.

Table 1: Heavier than Air

Gas

Sensor Location

Bottled LP (liquefied petroleum)

Propane

Butane

Gasoline

Trichloroethylene

Vaporized hydrocarbons

Hydrogen sulfide

Interior wall; 18-24" from floor.

§

D

O

N

OT

locate directly above or beside gas

appliances (ovens, heaters).

§

Avoid locating anywhere near a vent or window or

near an outside doorway.

Table 2: Lighter than Air

Gas

Sensor Location

Natural gas (methane)

Ammonia

Hydrogen

Near ceiling.

§

D

O

N

OT

locate directly above appliances where it is

subject to direct exposure to heat or steam.

Table 3: Same Density as Air

Gas

Sensor Location

Carbon Monoxide

4-6 feet above the (generally uniform) floor.

§

D

O

N

OT

locate in direct air currents of windows, doors, or vents.

Oxygen
Oxygen deficiency is usually caused by a gas that displaces the air in a space. The oxygen sensor should be located to
quickly detect the displacement of air by the gas. If a heavier than-air gas is involved in the application, locate the
sensor low in the space being monitored. Conversely, if a lighter-than air gas is involved, locate the sensor high in the
space. If there is doubt, call ENMET we will help you locate the sensor correctly.

Figure 6: Oxygen Cell Enclosure

Oxygen Sensor

Oxygen Sensor
Enclosure Bottom

Oxygen Sensor
Enclosure cover
(Cut away view)

Remove Shoring

Clip or Spring

O2 Cell Circuit Board
w/cell installed on circuit side

Orange Wire

Green Wire

Oxygen Cell
Bottom View