A message to our valued customers, vendors and friends,

On March 23rd, the Province of Ontario announced that all non-essential workplaces should close as of midnight tonight (Tuesday, March 24th) as part of the overall measures to control the spread of COVID-19.

With the release of the list we can confirm that we are an essential workplace and we will remain open for business and offer you our support. 

Click on the following for a link to our update: COVID-19 DEMESA Update

Un message à nos clients, fournisseurs et amis,

Le 23 mars, la province de l’Ontario a annoncé que tous les lieux de travail non essentiels devraient fermer à minuit ce soir (mardi 24 mars) dans le cadre des mesures globales de contrôle de la propagation de COVID-19.

Suite à la publication de la liste, nous pouvons confirmer que nous sommes un lieu de travail essentiel et nous resterons ouverts pour vous offrir notre soutien.

Cliquez sur ce qui suit pour un lien vers notre mise à jour: COVID-19 mise à jour de DEMESA

Instrument Sales

We have established relationships with reputable and leading manufacturers of safety and environmental instruments for all your monitoring solutions.  Whether you need a portable gas detector, PID or simply an indoor air quality monitor, you can count on our experience to help you get the right instrument for your application.

Calibration Gas

We are committed to providing our customers with accurate and reliable calibration gas standards. We offer a complete line of calibration gas, and accessories for safety, industrial hygiene, and instrument maintenance personnel.

Whether you are calibrating monitors for confined space entry, leak detection, area monitoring, combustion efficiency, or any other gas monitoring application, we are here to assist you in choosing the right gases.

Repair Service

Factory trained, with over 25+ years experience, we are confident you’ll get the best service the industry has to offer. All instrument repairs are done to manufacturers specifications and we only use factory replacement parts. We also provide you with a calibration certificate using NIST traceable standards for your records.

Fixed Systems

These are just some of the applications we can assist you with:

  • parking/service garage
  • refrigerant
  • methane
  • wineries

We offer full calibration service and we also install complete systems.

New Product

We are always trying to bring you the latest and greatest the industry has to offer. Talk to us about your application. We’ll keep looking until you’re happy with the instrument needed for your application.


The GX-3R is the world’s smallest 4-gas monitor! Weighing only 3.52 ounces, it clips comfortably within a worker’s breathing zone.

Both the GX-3R and the GX-3R Pro utilize a new generation of micro sensors.

  • The new LEL sensor has two active filaments to increase its resistance to silicone poisoning
  • The new O2 sensor has a 3 to 5 years life span
  • H2S and CO are now monitored by one combination micro-sensor
  • Available with a hydrogen compensated CO sensor (as LEL/O2/CO)
  • Non-compliance indicator
  • The sensors are field-replaceable: Easy to change in less than 60 seconds

GX-3R Pro

The GX-3R Pro is the world’s smallest 5-gas monitor. Weighing only 4.58 ounces, it fits in the palm of your hand.

In addition to the four confined space gases (CO, H2S, LEL, O2) the GX-3R Pro has a 5th channel for toxic and infrared sensors that can monitor, SO2, CO (with hydrogen compensation), ppm of CO2, % volume of CO2, HCN, NO2. Both CL2 and NH3 are scheduled to be released at the end of 2020.

Additionally, the GX-3R Pro comes equipped with:

• Two interchangeable sensor slots providing flexible configurations
• Non-compliance indicator
• Man-down alarm
• Panic alarm


altair 4xr, altair 4x, altair, msaOutfitted with rapid-response MSA XCell® sensors, the ALTAIR 4XR Gas Detector is the toughest 4-gas monitor on the market and is backed by a 4-year warranty. The ALTAIR 4XR can also provide real-time incident awareness to team members, supervisors, safety managers and others when paired with the MSA ALTAIR Connect app via a Bluetooth® wireless connection.