Principle Of Operation; Operating States; Monitoring Mode - Honeywell Satellite XT 9602-0400 FTT Manual To Operation

This section provides basic understanding of the instrument and its operation.
1.1

Principle of Operation

The Satellite XT is a gas monitoring instrument especially designed for the continuous
surveillance of hazardous gas concentrations. The instrument is designed to interface with
LONWORKS™ free topology systems. A free topology architecture allows the user to wire
gas monitoring instruments and control devices with virtually no topology restrictions
Power is supplied by a local 12 to 24 VDC power supply.
Target gas and measuring range depend on the type of sensor chosen. The sensor comes
with the specific data in its internal data memory. When a sensor is inserted, these data
are loaded into the instrument's internal memory.
Satellite XT versions FTT and FTT/R use electrochemical sensors for the surveillance of
toxic and corrosive gases at TLV levels (TLV = Threshhold Limit Value). The sensor output
signal is amplified electronically, digitised and the resulting concentration value is
transmitted to the communication network.
The Satellite XT FTT/C is used for monitoring combustible gases and vapours. This
instrument version uses catalytic sensors and is factory calibrated for the detection of
methane in air mixtures with concentrations up to 5 %-vol. (100 % LEL Lower Explosion
Limit). The sensor output signal is amplified electronically, digitised and the resulting
concentration value is transmitted to the communication network. To allow the surveillance
of a variety of other combustible gases, a correction factor called "K–Factor" can be
entered.
The Satellite XT FTT/R includes the relay option and provides 3 single-pole single-throw
relays for activation of external alarm devices. When the actual gas concentration exceeds
the alarm levels, the instrument will activate the appropriate alarm relay and display an
according message. A relay will also be activated in case of an instrument fault.
1.2

Operating States

There are four different operating states for the Satellite XT, Monitoring Mode,
Maintenance Mode, Warning Condition, and Diagnostics. Depending on the selected
operating state, the green status LED is either on, off, or flashing.
1.2.1

Monitoring Mode

The Monitoring Mode is the instrument's standard operating mode.
The green LED located above the <set> key is on.
In the Monitoring Mode, the instrument continuously monitors for hazardous gas
concentrations and checks for alarm levels and instrument faults.
The instrument's self-diagnostics provide on-line preventive maintenance information
identifying electronics or sensor problems. For example a sensor selftest is performed
every 24†hours. The sensor selftest is not available with instruments using oxygen
sensors or catalytic sensors.
Satellite XT FTT Versions
Basic Operation – Section 1
1-1