SD-3 series (gas detector heads with signal converter)
Explosion-proof fixed gas detector heads that continuously monitor combustible and toxic gases and oxygen. They have sensor degradation and life diagnosis functions.
Maker: Riken Keiki · Official product page
Specifications
| Detection method | Fixed type (diffusion, sampling, remote) |
|---|---|
| Target gases | Combustible gases, toxic gases, oxygen |
| Related models | SD-3EC / SP / NC / RI / GH |
| Main applications | Continuous monitoring of gas leaks |
Specifications as published by the maker. See the sources below.
Overview
The SD-3 series are Riken Keiki's fixed gas detector heads. They are used to monitor hazardous gases and raise alarms in industrial facilities. The electrochemical model covered here detects hydrogen sulfide (H₂S) and nitrogen dioxide (NO₂).
Detection can be chosen from diffusion (single type), sampling using an external unit, remote type that separates the SD-3SC main unit from a remote sensor unit, and duct insertion using a duct mount kit. It carries the higher-performance F sensor.
A flameproof explosion-proof structure suits harsh environments, with protection equivalent to IP66/67. It meets standards in many countries, including Japan Ex, IECEx, ATEX, China Ex and SIL. It runs on DC24V and offers a range of outputs, including RS-485 (Modbus-RTU), HART communication and operation via DTM.
Key features
- Electrochemical type (H₂S, NO₂)
- 4 methods: diffusion, sampling, remote and duct insertion
- Flameproof, equivalent to IP66/67
- Meets Japan Ex, IECEx, ATEX, SIL and others
Applications
- Monitoring and alarms for toxic gases in plants
Other gas detection systems
- PS-8 series · New Cosmos Electric
Sources
Last updated: October 23, 2026