SMC 4001 Gas Detection Controller

Sept. 24, 2021
Engineers responsible for toxic and combustible gas safety will find MSA's gas detection controller a reliable, modular solution.

The SMC Model 4001 Controller is a simple gas detection monitoring system designed for the user on a tight project budget. Born with the flexibility and features that meet the typical user’s safety requirements, this controller offers a no-fuss, dependable solution that prioritizes safety and mitigates risk to people, equipment, and plant operations. No complicated training is required, and set-up is done by a single technician in less than an hour with no special tools.


Designed for ease of use, the controller features a color LCD operator interface with menu-driven navigation accessed using a simple rotary push button to select and enter parameters on the display panel. Display colors change based on the alarm state: Green is Normal, Yellow is Warning, Red is Alarm, and Blue is Fault.


This controller’s three relays are Form C SPDT’s, rated at 5 Amps each to connect to notification systems and appliances. The relay action can be selected as non-latching or latching with a remote-acknowledge input. Its Modbus RTU output is provided for connection to various supervisory systems, or an optional gateway. The controller’s analog output is a 2-wire retransmission of the measured input for trending or recording.


The modular design features a choice of two, four, or eight-channel configurations to provide application flexibility for process engineers responsible for small to mid-size plants. Industry-standard 2, 3 or 4-wire analog 4-20 mA input with HART V7 is included with the controller. An industry standard 120/240 VAC to 24 VDC power supply is supplied as well.


SIL 2 rated, the controller is well suited for municipal water or wastewater treatment hazardous environments and features a rugged NEMA 4X enclosure for wet, dirty environments where toxic or combustible gases are present.  Other approvals include UL 62368-1/CSA C22.2 No. 62368-1; UL-508A.

  • Modular design allows 2, 4, or 8 channel configurations
  • Rugged NEMA 4X enclosure protects in wet or dirty environments
  • 0-20 mA analog input/output
  • Three 5 amp relays for field devices and notification systems
  • RS-485 Modbus RTU output for remote monitoring with Cloud connectivity