For more information

Sentry Gas Detection System

Sentry Gas Detection System provides a comprehensive plant-wide controller/sensor system for monitoring combustible gas, oxygen deficiency and toxic gases to maintain safety in a plant. The flexibility of Sentry enables the user to design a safety system that meets his specific needs. Even the basic system includes multiplexed sensors, non-intrusive calibration and RFI/EMI immune digital sensor communication.

Note: Move your mouse over each component in the graphic below to learn more about Sentry. Click on Expanded Sentry System icon to learn how it can be expanded to meet your specific requirements.

Gas Detection System

Sentry gas detection systems provides the flexibility and expandability sought by safety and instrumentation engineers worldwide for plant-wide hazardous gas monitoring needs in a broad range of industrial applications. Implementing the concept of Gas Risk Management in a flexible, easy to operate system, Sentry offers the alarm logic, event response and critical data retention to insure that your safety requirements are met and that your due diligence is documented.

Sentry Features

  • Digital communications
  • Multiplexed sensor interface
  • Internal self-diagnostics
  • Modbus communications
  • LANServer
  • Multiple output protocols available
  • Addressable Output Module
  • Analog output
  • Flexible relay logic configuration
  • Real time status reporting
  • Historical data collection
  • Alphanumeric error messages
  • EMI/RFI immune
  • Various mounting configuration
  • Password protection
  • FM Approved
  • CE Marked
  • High density – 32 channels in 19” rack
  • Printer output
  • Remote display/relays option
  • Non-intrusive calibration
  • Analog sensor input option
  • Central alarm controller – Commander

For more information

Sentry Gas Sensors

sentry gas sensorsSentry utilizes digital RS-485 digital communication between the smart remote sensors and the controller to controller interface assuring RFI and EMI immunity over extended distances. The two way digital communication between the sensor and controller results in easy one-person, non-intrusive calibration and extensive diagnostic features.

Sentry Multiplexing

sentry multiplex

Multiplexing of digital signals from sensors to controller on a common cable reduces installation costs. Up to eight sensors can be multiplexed on a single cable. Since each sensor has a unique address, the controller can communicate with the sensors in turn.

Sentry Power

In addition to 120 VAC power for the controller, Sentry can also use 220 VAC or 12-24 VDC power from battery backup systems available from Sierra Monitor.

Common Alarm Output Relays

Sentry provides as standard DPDT dry contact relays for low alarm, high alarm and trouble alarm. Any one sensor can activate the appropriate relay. Additional individual alarm relays are available.

Sentry Printer

Sentry’s preformatted reports provide critical information for analyzing gas exposure and evauating system reliability. These reports help the user make better decisions during a gas leak, provide history for due diligence and confirm reliability of the system.

Sentry Controller

Gas DetectionThe heart of any Sentry system is the controller. In addition to providing visual output of gas concentration and alarm conditions, the controller is a centralized system for diagnostics, sensor calibration, system security, and report generation. The easy-to-use menu prompting makes it simple to configure the system. LEDs indicate the alarm status for each sensor, and the two LCD displays quickly provides the user the information needed to maintain safe conditions in the plant.