De Nora Capital Controls CHLORALERT 17CA3000 Series - 3 Functional Description; General; Features; Sensors;Transmitter

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3.0 FUNCTIONAL DESCRIPTION
3.1 General
The 17CA3000 Chloralert Plus normally consists of two distinct elements, the sensor/transmitter and the receiver.
The sensor/transmitter is located near potential sources of gas leaks or emissions while the receiver is located
remotely in a control room, although in some instances, they may both be located at the same site.
Both elements of the device have inputs and outputs. The sensor/transmitter is powered by the receiver to
operate the electronics as well as the sensor, it transmits a multiplexed frequency-modulated (FM) signal to
the receiver. This conditioned sensor signal is a function of the gas concentration being monitored by the
sensor. The receiver accepts the sensor/transmitter input, converts it to a display of the gas concentration,
activates alarms and other safety devices, and transmits an analog output current signal (if so configured) for
recording or control purposes. Additionally, setup and configuration data are available via an optional remote
serial data communications port. The receiver may also receive information such as that needed for a set up
and calibration from an external computer via this datalink (Refer to section 6.0).
The receiver is also used to set up the database for the various alarm functions and the required calibration
information. Several alarm modes are available; Instantaneous, STEL, TWA, or Custom. It also provides
information during the calibration procedure about the status of the calibration as it proceeds.
The main board in the receiver contains the power supply for all sensor/transmitters, the microprocessor, three
(standard) programmable alarm relays and associated electronics. Four optional features are available:
• Four 0-20 mA or 4-20 mA ANALOG OUTPUTS for transmission of the gas
concentration levels.
• Six additional DIGITAL OUTPUT relays
• RS232 or RS485 Communications Port
• Battery Backup
The purpose of this chapter is to give an overview of some of the features of the 17CA3000. For actual
operational and data-entry procedure, refer to section 4.0.
3.2 Features
3.2.1 Sensor/Transmitter
3.2.1.1 Gases
Presently, the system is designed to monitor two gases:
• Chlorine
• Sulfur Dioxide
3.2.1.2 Gas Concentration Range
The Chloralert™ Plus uses frequency to transmit the sensor/transmitter information to the
receiver. The accuracy for any given concentration is then determined by the concentration
used for calibration.