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FAQs

** Under construction  - feel free to submit queries **

Software & Interfacing
What is RS422?
Why does it have an RS422 interface and not RS232?

Can I use any RS422/RS232 to USB interface ?
Is there a wireless version ?
Is there an Ethernet version ?

Installation, wiring etc
What environmental issues should beconsidered when choosing a mounting location?
Will it detect small children/animals etc.?
Can I hide it behind a glass/plastic window etc. ?

Applications
Can I get absolute temperature measurements from the image data?
Can it be used for accurate room-occupancy monitoring

Miscellaneous
I'm doing a tempory installation & want to use Thermitrack - do you do rentals ?


Software & interfacing

What is RS422?
Why does it have an RS422 interface and not RS232?

RS422 is an industry-standard high-speed serial interface designed to give reliable performance over long distances. The data format is identical to RS232, only the electrical levels are different.
RS422 was used to ensure the most reliable operation over long cable distances (up to 100 metres) at high baudrates.
RS422 is also the hardware interface used by the widespread DMX512 lighting standard. With application-specific custom firmware, the standard Thermitrack hardware can drive DMX devices directly, with no need for a seperate control system. A hardware build variant is also available which can drive two DMX universes.

Can I use any RS422/RS232 to USB interface ?
In principle, yes, however due to the different nature of USB and RS232 communication, there can be issues of latency and data throughput which can cause problems especially when using image data, due to the high throughput. The configuration of the Thermitrack dedicated USB interface has been carefully optimised for best performance, and in many cases it will outperform a 'real' RS232 port.  The dedicated USB interface also contains a power converter to allow one Thermitrack camera to be powered from the USB port.

Is there a wireless version ?
Is there an Ethernet version ?

No. As it needs a mains-derived power supply, wiring will always be necessary. However it could be used with one of the various existing RS232-to-wireless  and RS232 to ethernet converter products available.

Installation etc.

What environmental issues should beconsidered when choosing a mounting location?
Although Thermitrack is 'blind' to all visible light sources, any moving objects in the direct field of view are likely to be seen, as their temerature will usually be different from the surroundings. Avoid pointing at things like doors, moving-head lights, curtains, fans etc. Things like incandescent lights are generally OK, even if flashing, as the rate of temperature change will usually be slow enough to not be 'seen'.
Although static or slowly-changing heat sources in the background will generally not be visible, any background features which are above body temperature may cause disruptions in tracking people moving in front of them, as the camera will see the 'warm' target suddenly turn 'cold' as it passes a background object above its temperature. 
It is essential for Thermitrack to have a solid & stable mounting, as any movement (e.g. swaying) or vibration will very severely impair tracking performance.
Warm or cold air currents are generally not a problem in themselves, but could cause problems if they can cause rapid temperature changes or movement in objects in the field of view (e.g. curtains).

Will it detect small children/animals etc.?
Yes, however as the normal mounting height range is specified for detection of adults, for reliable detection of smaller targets, you may need to avoid the upper limits of the mounting height range.

Can I hide it behind a glass/plastic window etc. ?
No. The long wavelengths used by the camera will only pass through a very limited number of exotic materials. If you need to conceal Termitrack, you need to use a window which will pass wavelengths between 6 to 12 microns. Germanium and Zinc selenide are the most commonly used materials, but even these will attenuate the signal to some extent. Small windows made from these materials are available, but it is recommended that samples are tested carefully to check that performance is adequate. Thin germanium windows in stock sizes typically cost around GBP1 per mm of diameter. Surplus germanium and zinc selenide optical parts can occasionally be found cheaply on Ebay.

Applications

Can I get absolute temperature measurements from the image data?
No. The camera only measures the rate of change of temperature. This is why you typically see a 'cold shadow' behind a moving target. More expensive thermal imaging cameras typically use a mechanical shutter to convert absolute temperatures into a changing signal to measure absolute temperature, but this is not necessary for tracking applications. You can however vary the brightness and contrast of the image data to get some control over the range of temperatures seen, e.g. you can de-sensitise to detect flames. This adjustment only affects image data, not tracking, the sensitivity of which is not adjustable.

Can it be used for accurate room-occupancy monitoring
It depends. Although you can get good data on movements into, out of and around spaces, due to the fact that the camera only sehnses chnages in temperature, targets that are stationary for more than about 8 seconds will fade out and disappear. In some cases it may be possible to intelligently deal with this based on location (e.g. an object disappearing in the middle of the room is probably a fade-out rather than an exit)

Miscellaneous

I'm doing a tempory installation & want to use Thermitrack - do you do rentals ?
This may be possible - please email to discuss