[labnetwork] Toxic Gas Monitoring Systems

[Hathaway, Malcolm]

Hi Jerry,

At Harvard CNS, we have a monitoring system created by Hallam-ICS, using around 90 sensors, a mixture of Midas sensors (allows modestly remote sampling - 10-100 ft depending on gas) and MST sensors (can be made explosion-proof, for use in gas bunker).  Both are currently from Honeywell.  We have also heard good things about DOD Technologies "Cosmos" sensors. 

We use 4-20mA current loop output from sensors to the Hallam system.  Four levels of alert go to our Siemans building control system, relayed to our University Operations Center, where a "Dialogic" system sends out email and phone alerts.  The four levels are for high and low level ambient gas sense events, "enclosure" gas sense events (in exhausted enclosures like gas cabinets, etc), and sensor faults.  All gas sense events trigger local or general evacuations, and all ambient gas sense events tie into the building fire alarm system.  All sense events also shut off gas cabinets and VMBs (valve manifold boxes) appropriate to the detected gas. 

Gas sense events of various types, and sensor faults, are communicated through the Hallam system, triggering alarms and alert calls and emails.  A bit of system monitoring is also included, which sends out email alerts to the system administrators when other conditions exist which might effect the over-all system functionality, such as network issues between the Hallam TGMS and the Siemans system, horns or strobes turned off for testing or maintenance, network issues within the Hallam system, connection status between the TGMS and the fire alarm system, etc.  

The Hallam system (the "TGMS") is able to store a lot of log data, and show graphical traces of all monitored signals.  It also allows us to go back and check times and details on any "events", viewed on touch-screen monitoring terminals called SCADAs.

Hallam's most recent revision of their software includes the ability to choose different vendors' sensors, with each sensor point being individually configurable.

We have a separate "Remote Monitoring" PC which mirrors the TGMS monitoring "SCADA" nodes, which PC we can access from off-site via Remote Desktop Connection in Windows.   

We have a company called EERC come up every 4 months to do response "bump" testing. 

So far, it all seems to work pretty well.  


Mac Hathaway
Senior Process Engineer
TGMS Administrator
Harvard CNS
617-495-9012



_______________________________________
From: labnetwork-bounces at mtl.mit.edu [labnetwork-bounces at mtl.mit.edu] On Behalf Of Bowser, Jerry [jerry.bowser at nist.gov]
Sent: Wednesday, August 08, 2012 1:13 PM
To: 'labnetwork at mtl.mit.edu'
Subject: [labnetwork] Toxic Gas Monitoring Systems

Hello All,

I wanted to survey the group for information regarding the type and brands of toxic gas monitoring control systems in use.

Here at the CNST, we use various gas sensors (about 55) connected to a custom PLC based system that is just about at capacity.  If a gas is detected, the system shuts down gas cabinets, sounds alarms, and alerts our fire department.  The major shortfall of the system is that the detection level can be read at the sensor in the detection zone but is not displayed at the control interface.

Before we decide on upgrading or replacing our control system, I thought I would see what others are currently using.  Thanks for your input.

Jerry



*******************************************
Jerry Bowser
NanoFab Operations Group
Center for Nanoscale Science and Technology
National Institute of Standards and Technology
Phone: (301) 975-8187