Miracle Alarm Sensor? (Xandem)By: Brian Rhodes, Published on Jun 10, 2012
If we told you a security system could see through walls, is invulernable to false alarms and works with yout existing intrusion system, would you think it is a con or the next big thing in security? Well, a US based startup in the super lower innovation alarm market is claiming to do this. In this note, we dig into the details of the offering, examining its pros and cons.
To start, here's a news clip from a local TV station that does a good job introducing the aspirations of the technology / approach:
Do Xandem TMD sensors have an advantage over existing sensor types? We break down the Pros and Cons of the offering into the following list:
More precise: The Xandem TMD (Tomographic Motion Detection) sensor uses a tomographic mesh to detect movement. When an object moves - regardless of velocity or mass - inside the mesh, the detected movement can be used to trigger alarm systems. Sensitivity thresholds are set to minimize false alarming.
Overcomes traditional sensor weakness: The strongest advantage of the TMD sensor is that it overcomes weaknesses of traditional movement detection sensors. For example, Passive Infra Red (PIR) sensors detect change in heat energy. Subsequently, rogue sources of heat (HVAC vents, intense light spots, sun movement) can trigger false alarms. Because the TMD sensor uses ambient radiation to detect movement, the traditional culprits of false alarms are not a weakness. Likewise, inorganic sources of radiation are not as powerful as organic sources (eg: human beings) so the most likely sources of interest are easily detected.
More resolute: The increased resolution of the TMD sensor could be a benefit in certain deployments. While a typical motion detectors define movement within gross 'zones of detection', a TMD sensor produces a mesh that surrounds an area completely. Not only does this prevent blindspots, but the layering cumulates into a very resolute field of detection.
Universal Retrofit: Unlike specialty sensors that communicate with proprietary protocols, the TMD sensor package can trigger alarms in any existing intrusion alarm system. The sensor system's central 'programming module' (PM) node can be wired into an alarm panel similar to any existing sensor using onboard 'Normally Closed' contacts. When motion is detected in the field, the PM node opens the alarm circuit in the panel and results in an alarm condition.
Higher Installation Cost: The TMD sensors are not as easy to install as existing sensors. Not only are system sensors more numerous that simple door/window contacts, each TMD sensor requires fine tuning and sensitivity adjustment so that movement outside the area does not trigger alarms. Some construction materials absorb more radiation energy than others, and each sensor much be tweaked according to the specific environment that it is installed. Additionally, each sensor must be mounted approximately 3' above the floor for maximum effect. While sensors can be easily mounted within walls, retrofit applications have a significant cosmetic issue to address. While the semi-exposed sensor location may not be an issue in some commercial or industrial environments, it is sure to be a problem in architecturally sensitive or residential applications without requiring significant drywall or masonry work.
Higher Product Price: The most stark difference compared to traditional sensors is price. Unlike single door/window contacts or PIR sensors that are installed one at a time, Xandem requires a mesh of sensors to be installed. While the manufacturer has not yet finalized pricing, they report that sensor kits will be available between $600 to $2000 depending on kit size. Considering that typical PIR sensors sell for as little as $20, this marks a steep price difference for similar coverage.
Cost of Ownership: Because the TMD system is composed of many individual nodes, the cost of maintenance and sensor adjustment becomes a big potential cost. When a PIR sensor 'goes bad', it can be easily unwired and replaced. However, if a TMD sensor is 'buried' within a wall, the cost of servicing or replacing that sensor is significantly more costly.
While the sensor technology is not limited to only being used in intrusion alarms systems, the relevant technical specification points for detection alarms are summarized below:
- Wireless sensor uses radiation monitoring rather than thermal change to detect movement
- Technology sees through stationary obstructions like walls
- Once deployed, sensors network provides 'real time' location of intruder
- Sensors built with NC contacts, and can be wired to any existing intrusion system
- 25 - 35 sensors needed to cover a medium single floor house
- Pricing not finalized, but the developer estimates pricing between $600 - $2000 per kit depending on kit size
Xandem represents a new type of sensor technology still widely untested commercially. Availability is not expected until the end of 2012. The company has several extended beta/field tests ongoing, but commercial viability and system performance is still unproven. Since no accurate assessment of extended performance can be made, we cannot comment on its suitablity for deployment. However, because of the fundamental difference in sensing technology this product possess, it is worth keeping tabs on. We intend to continue to track development and future deployment of this product, and will keep our readers posted.