Gas detection equipment benefits from international co-operation.


Critical Environment Technologies Canada Inc. (CETCI) was founded by Frank and Shirley Britton in 1995. Since that time, the company has expanded considerably and now employs around 35 people; developing and manufacturing gas detection equipment for global markets. One of the keys to the company’s success has been the relationship that it has built with sensor supplier Alphasense.

Frank’s career in gas detection stretches back to 1982, and when he was first visited by a sales person from Alphasense in 2003, he was immediately impressed with the representative’s technical knowledge. “It was clear that he understood the issues that manufacturers face, and had a good knowledge of the challenging applications in which our equipment is commonly deployed. This was important, because it helped to build trust.”

Following that initial meeting, it was agreed that CETCI would trial some of Alphasense’s electrochemical gas detection sensors, and Frank was pleased to see how well they performed. “It was also very encouraging to note the high level of service that we enjoyed,” he adds. “Even though there were 5,000 miles between us and 8 hours in time difference, we have always received very prompt and useful responses to our service requests.

“In fact, I would go so far as to say that Alphasense has delivered superb levels of service from day one, and as a consequence is one of our best suppliers. It is also very useful that Arthur Burnley from Alphasense visits us every year to review progress and explore new ways for us to work together in the future.”

YesAir portable

As the relationship with Alphasense has grown the range of sensor technologies employed has expanded to include electrochemical, catalytic, optical, metal oxide and PID. For example, some of these sensors are deployed in portable indoor air quality instruments such as the YESAIR range. Available in two models (pump or diffusion) and battery powered with onboard datalogging, the YESAIR instruments have been designed for intermittent or continuous indoor air quality monitoring of temperature, RH, particulates and up to 5 gases. Each can be configured with parameter selection from more than 30 different plug and play gas sensors, as well as a particulate sensor.

CETCI also manufactures fixed gas detection systems, controllers and transmitters that are deployed to monitor hazardous gases; protecting health and safety in confined spaces and indoor environments. Customers are able to select from a range of target gases including Ammonia, Carbon monoxide, Chlorine dioxide, Chlorine, Ethylene, Ethylene oxide, Fluorine, Formaldehyde, Hydrogen, Hydrogen sulphide, Hydrogen chloride, Hydrogen cyanide, Hydrogen fluoride, Nitric oxide, Nitrogen dioxide, Oxygen, Ozone, Phosphine, Silane, Sulfur dioxide, Methane, Propane, Hydrogen, TVOCs and Refrigerants. The company’s products are employed in commercial, institutional, municipal and light industrial markets, and in a wide variety of applications. These include refrigeration plants, indoor swimming pools, water treatment plants, ice arenas, wineries and breweries, airports, hotels, fish farms, battery charging rooms, HVAC systems, food processing plants, vehicle exhausts and many more.

One of the main reasons for CETCI’s success is its ability to develop gas detectors that meet the precise requirements for specific markets. “We are large enough to employ talented people with the skills and experience to develop products that meet the latest requirements,” Frank explains. “But we are not so large that we are uninterested in niche applications – in fact we relish the challenge when a customer asks us to do something new, and this is where our relationship with Alphasense, and the technical support that they can provide, comes into its own.”

The market for gas detection equipment is constantly changing as new safety and environmental regulations are created around the world, and as new markets emerge. Again, the close relationship with Alphasense is vitally important; as new sensors are being developed, CETCI is moving into new markets that are able to utilise these technologies.

New market example – cannabis cultivation
Following the legalisation of marijuana in Canada and some other North American regions, greenhouses and other plant growth rooms have proliferated. These facilities can present a variety of potential hazards to human health. Gas powered equipment may be a source of carbon monoxide; carbon dioxide enrichment systems may be utilised; air conditioning systems can potentially leak refrigerants, and propane or natural gas furnaces may be employed for heating purposes. All of these pose a potential risk, so an appropriate detection and alarm system is necessary.

Responding to market demand, CETCI developed monitoring systems that met the requirements of the market. This included appropriate gas detectors connected to a controller with logging capability and a live display of gas levels. In the event of a leak or high gas concentration, the system can provide an audible or visual alarm, and relays can be configured to control equipment such as the ventilation system or a furnace.

Developing market example – car parking facilities

Car park installation

In recent years, the effects of vehicular air pollution on human health have become better understood, and received greater political and media attention. As a result, the owners and operators of parking facilities have become more aware of the ways in which they can protect their customers and staff.

Carbon monoxide is a major component of vehicle exhaust, and nitrogen dioxide levels are high in the emissions of diesel powered engines. In more modern facilities, hydrogen may accumulate as a result of electric car charging stations. CETCI has therefore developed hazardousgas detection systems to protect air quality in parking locations. This equipment includes output relays which can minimise energy costs by controlling the operation of ventilation systems.

Summarising the secrets to a long and successful partnership in gas detection, Frank says: “One of the most important issues is of course the quality of the products, and we have always been impressed with the fact that Alphasense differentiates itself from other sensor manufacturers by testing every sensor.

“The next important issue is the quality of service; we need sensors to be delivered on time and in perfect condition, and when we have a technical query we have become accustomed to a very prompt response.

“We also value highly the opportunity to develop our businesses together – through regular conversations with Arthur and his colleagues we are able to plan our future product development and marketing strategies, so that we can meet the ever changing needs of the market. This has worked extremely well for the last 17 years and we foresee it doing so for many years to come.”


#Environment #Alphasense @cetci @_Enviro_News

Inertial Measurement Unit – essential in self-driving cars!

They are here or on the way – the self-driving car! It is one of revolutions which could change lives in the 21st century. Here Mike Horton, Chief Technical Officer at ACEINNA discusses seven reasons your life depends on an accurate IMU (Inertial Measurement Unit) in these self-driving cars.

An inertial measurement unit (IMU) is a device that directly measures the three linear acceleration components and the three rotational rate components (6-DOF) of a vehicle. An IMU is unique among the sensors typically found in an autonomous vehicle because an IMU requires no connection or knowledge of the external world.

A self-driving car requires many different technologies, for example — LIDAR to create a precise 3-D image of the local surroundings, radar for ranging targets using a different part of the EM spectrum, cameras to read signs and detect color, high-definition maps for localization, and more. Unlike the IMU, each of these technologies involves the external environment in order to provide data back to the software stack for localization, perception, and control. This unique “independent” property of the IMU, makes it a core technology for both safety and sensor-fusion.

An Accurate IMU can Mitigate Issues in RED

The following of Seven Top Reasons is just a start, additional reasons and benefits of an accurate IMU are welcomed as responses to this post either as comments or direct to the author himself at ACCEINNA.

•1 Safety First
The system engineer needs to consider every scenario and always have a back up plan. Failure Mode Effects Analysis (FMEA) formalizes this requirement into design requirements for risk mitigation. FMEA will ask what happens if the LIDAR, Radar, and Cameras all fail at the same time? An IMU can dead-reckon for a short period of time, meaning it can determine full position and attitude independently for a short while. An IMU alone can slow the vehicle down in a controlled way and bring it to a stop … providing the best practical outcome in a bad situation. While this may seem like a contrived requirement, it turns out to be a fundamental one to a mature safety approach.

•2 A Good Attitude
An accurate IMU can determine and track attitude precisely. We often think of a car’s position or location, but when driving the direction or heading is equally crucial. Driving the slightly wrong direction even for a brief instant, will put you in the wrong lane. Dynamic control of the vehicle requires sensors with dynamic response, and an accurate IMU does a nice job of tracking dynamic attitude and position changes accurately. Due to its fully environment independent nature, an IMU can even track the really tricky cases such as the slipping and skidding where tires lose traction. A precise attitude measurement is often useful an input into other algorithms. While LIDAR and Cameras can be useful in determining attitude, GPS is often pretty useless. Finally, a stable independent attitude reference has value in calibration and alignment.

•3 Accurate Lane Keeping

During turns, an accurate IMU plays a key role in lane keeping

It turns out when humans are not distracted or drunk, we are typically not bad at driving. A typical driver can hold their position in a lane to better than 10cm. This is actually really tight. If an autonomous vehicle wanders in its lane, then it will appear to be a bad driver. As an example during a turn, poor lane keeping could easily result in an accident. The IMU is a key dynamic sensor to steer the vehicle dynamically, moreover the IMU can maintain a better than 30cm accuracy level for short periods (up to ten seconds) when other sensors go offline. The IMU is also used in algorithms that can cross compare multiple ways to determine position/location and then assign a certainty to the overall localization estimate. Without the IMU, it maybe impossible to even know when the location error from a LIDAR solution has degraded

•4 LIDAR is Still Expensive
Tesla is famous for its “No LIDAR Required” approach to autopilot technology. If you don’t have LIDAR, a good IMU is even more critical because camera-based localization of the vehicle will have more frequent periods of low-accuracy simply depending on what is in the camera scene or the external lighting conditions. Camera based localization uses “SIFT” feature tracking in the captured images to compute attitude. If the camera is not stereo (often the case) inertial data from the IMU itself is also a core part of the math to compute the position and attitude in the first place.

•5 Compute is not Free
The powerful combination of high-accuracy LIDAR and high-definition maps is at the core of the most advanced Level 4 self-driving approaches such as those being tested by Cruise and Waymo. In these systems LIDAR scans are in real-time matched to the HD map using convolutional signal processing techniques. Based on the match, the precise location of vehicle and attitude is estimated. This process is computationally expensive. While we all like to believe the cost of compute is vanishingly small, on a vehicle it simply is not that cheap. The more accurately the algorithm knows its initial position and attitude, the less computation required to compute the best match. In addition, by using IMU data, the risk of the algorithm getting stuck in a local minimum of HD map data is reduced.

•6 GPS/INS: Making High-Accuracy GPS Work
In today’s production vehicles GPS systems use low-cost single-frequency receivers. This makes the GPS accuracy pretty useless for vehicle automation. However, low-cost multi-frequency GPS is on the way from several silicon suppliers. On top of this upcoming silicon, network-based correction solutions such as RTK and PPP can provide GPS fixes to centimeter level accuracy under ideal conditions. However, these solutions are very sensitive to the environment — such as bridges, trees, and buildings. It is well established that the way to overcome this challenge and improve precisions GPS reliability is to use high-accuracy IMU aiding at a low-level in the position solution. Such GPS/INS techniques include tightly-coupled and ultra-tightly-coupled GPS/INS. These are coming soon to the automotive market (stay tuned for exciting updates).

•7 Car’s Already Need an IMU
Turns out production automobiles already have anywhere from 1/3 of an IMU to a full IMU on board. Vehicle stability systems rely heavily on a Z-axis gyro and lateral X-Y accelerometers. Roll-over detection relies on a gyro mounted with its sensitive axis in the direction of travel. These sensors have been part of the vehicles safety systems for over a decade now. The only problem is that the sensor accuracy is typically too low to be of use for the prior six uses cases. So why not upgrade the vehicle to a high-accuracy IMU and help it drive autonomously? The main barrier has been cost.
Aceinna along with other companies in the industry are working hard to remove the cost barrier.

Pushing the boundary of price-performance

@MEMSsensortech #Automotive