Introduction; General - Honeywell 705 Operating Instructions Manual

MAN0363.PM6 Issue 02, Aug 97
00705M5002

1.1 GENERAL

The 705 Sensor (Figure 1) is a combustible gas detector
certified for installation in a hazardous area. This version
uses the catalytic principle and in conjunction with electronic
control equipment situated in a non-hazardous area it forms
a combustible-gas detection system. The type of sensor
and the gas to be detected should always be quoted when
ordering replacement sensors.
The sensor comprises an aluminum housing containing a
pair of poison resistant detector elements, with a sintered
stainless steel disc forming the face of the sensor. The
housing has a 47mm AF body with a 3/4 NPT mounting
thread at one end and an M36 accessory thread on the
other end. A plastic Filter Housing screws on to the
accessory thread and holds the filter in position, if required.
There are a number of accessories available for the 705
Sensor which utilise the M36 accessory thread. Refer to
Section 8 for alternative systems to which the 705 Sensor
can be connected.
Note:

1. INTRODUCTION

New Sensors are despatched with a protection disc
in place of a filter. This disc should not be removed
until the sensor is installed or commissioned.
Figure 1 Type 705 Sensor and Filter Housing
Mounting Thread
Accessory Thread
Sintered Disc
Hydrophobic Barrier
(fit white side out)
Filter Housing
7
705 Sensor