CTI GG-VL2-NH3, Инструкция по установке и эксплуатации

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GG-VL2-NH3
General Description Installation
The GG-VL2-NH3 sensor is a +24 VDC, three-wire,
4/20 mA sensor for ammonia. It provides an industry
standard linear 4/20 mA output signal compatible with
most gas detection systems and PLCs.
The GG-VL2-NH3 provides real-time continuous
monitoring of ammonia vapors in refrigeration
system vent lines. Utilizing a long-life ammonia
selective catalytic bead sensor, the GG-VL2-NH3
sensor can withstand occasional exposures to high
concentrations of ammonia without shortening the life
of the sensor.
The sensor element can be accessed from inside
of the stainless steel enclosure, and is sealed from
the vent line to prevent ammonia from entering the
enclosure.
The transmitter circuit board is sealed in potting
compound, protecting sensitive electronic
components and copper tracing from corrosion.
Recommended alarm setpoints for ammonia system
vent lines are typically 0.5% to 1.0% NH3 (12 to 20 mA).
Locating the sensor
Note: The ½” nipple of the supplied mounting kit
should be welded to the relief header to allow airflow
to the sensor.
Note: Removing the ½” plug from the mounting
kit usually allows more fresh air to the sensor
and prevents signal rise over time. Since fresh air
promotes longer sensor life and overall long-term
sensor performance, it is recommended that the
sensor is installed outdoors.
Discharging to Atmosphere
The GG-VL2-NH3 sensor assembly should be installed
outdoors three to five feet above the roofline, where
the relief header discharges to the atmosphere (see
Figure 1).
Discharging to Diffusion Tank
The GG-VL2-NH3 sensor assembly should be installed
on the atmospheric vent on top of the water tank (see
Figure 2). This type of installation will not catch the
weeping relief valves, but will detect ammonia vapors
from the water during a release event.
Caution: Installation of the sensor between SRV’s
and the diffusion tank will not allow fresh air in, so
any introduction of ammonia gas will stay trapped in
the header, resulting in a continuously high signal.
A compressed air purge may be required for this.
Contact Calibration Technologies for details.