Introduction; Device Overview - Teledyne Meridian User Manual

3. Introduction

3.1. Device Overview

The Meridian Universal Gas Detector (also referred to as "the device") is a fixed-point detector designed to pro-
vide continuous monitoring of combustible gases (range = 0 to 100% LEL) and toxic gases (range varies based on
sensor type).
The device receives inputs from up to three (3) Meridian detector bodies and transmits the output to a remote mon-
itoring system. The Meridian detector bodies can be used for these applications based on the installed sensor:
• To detect toxic gases in ambient atmospheres, the device accepts electrochemical (E-Chem) sensors. Tradi-
tional, as well as Rock Solid, sensors are available.
• To detect hydrocarbon combustibles in ambient atmospheres, the device accepts either catalytic bead (Cat-
bead) or miniaturized infrared (IR) sensors. Miniaturized IR sensors are also used to detect carbon dioxide
(see Appendix A. Specifications).
NOTE: Except where noted, the type of sensor installed does not affect the functionality of the
device.
Standard device features include:
• Selectable Sensor Ranges – Multiple ranges available to match your application needs.
• An LCD – Provides quick, easy user interface (UI) to menus. The LCD may be installed in multiple orientations
using its pluggable design and is also visible in bright sunlight. An optional heated LCD is available for cold
conditions.
• Four (4) Alarm LEDs (ALM1, ALM2, ALM3 and FAULT) – For field equipment alarm levels.
• Truly Universal – Accepts all sensor types and retains approvals regardless of which sensor is installed.
• Non-Volatile Memory (NV-EEPROM) – Retains all configuration parameters of the device in the event of a
power interruption or loss.
• Equipped with MODBUS RTU (RS-485) Communications capabilities – Supports up to 247 addressed
remote terminal units (RTUs). Up to 32 RTUs per loop.
• Automatic Calibration – Count down timer ensures sensor zero and span calibration for better detection and
safety of personnel and property.
• Multiple Navigation Keys – Enables device configuration, calibration and fault analysis without opening the
enclosure.
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MERIDIAN
UNIVERSAL GAS DETECTOR
INTRODUCTION
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