Spectrex Quasar 900 Open-Path Gas Detection System - Manual (Page 18)

SafEye TM Quasar 900 Gas Detector
6 Principle of Operation
2.3.8 Heated Optics
SafEye Quasar includes heated optics for the Detector and source. The
heater increases the temperature of the optical surface by 5-8°F (3-5°C)
above the ambient temperature to improve performance in icing,
condensation and snow conditions. The heated optics is configured to
automatically operate when the change in temperature requires the heating
(default).
However, the heated optics can be defined as one of the following modes:
1 Not operated (not an option on source unit)
2 On continuously
3 Automatic, per temperature change (default)
See System Setup, page 16.
When operated ‘per temperature change’, the user can define the start
temperature below which the window will be heated (default 41°F (5°C)).
This temperature can be defined between 32°F (0°C) to 122°F (50°C). The
heating will stop when the temperature is 27°F (15°C) above the start
temperature.
2.3.9 HART Protocol
The Quasar 900 uses the HART Protocol.
HART Communication is a bi-directional industrial field communication
protocol used to communicate between intelligent field instruments and host
systems. HART is the global standard for smart instrumentation and the
majority of smart field devices installed in plants worldwide are HART-
enabled.
HART technology is easy to use and very reliable.
Through the HART connection, the SafEye is able to perform:
 Detector set-up
 Detector troubleshooting
 Detector health and status
For more details, refer to the HART Manual TM 888030.
The HART communication can be connected on the 0-20mA line or through
the IS connection with a standard Handheld loaded with our host software
and a special harness.
2.3.10 Handheld Unit
The I.S.-approved handheld diagnostics unit (Part no. 799810) is available
to make installation and maintenance easier. This is an all-on-one diagnostic
/ calibration / interrogation plug-in unit that allows for one-person
installation and maintenance.