Oh, The Pressure!

With today’s video technologies continuing to rise in complexity and cost, the pressure of making the right decision… well… The “pressure” here is not the pressure of decision, it is the decision of pressure.

Decision: A pressurized outdoor camera or a sealed outdoor camera (non-pressurized)?

Why have pressurized cameras?

Typically, the location of the camera will be in an area that is known to have some type of air-borne contaminants that could damage the internals of the camera. Contaminants can be anything from oil, water, or any particulate matter from manmade or natural occurrence. The thought here is that if the camera is internally pressurized above ambient pressure, these contaminants will be prevented from entering.

The core purpose of pressurization in an outdoor camera is to “ensure that no water, moisture or dust is able to enter the camera enclosure and cause premature failure of the electrical, mechanical or optical components.”

The above quote was taken from a previous blog entitled “Dry As A Bone” in describing the challenge of building an outdoor camera; to read the entire article click on the link below:

http://gotowti.typepad.com/my_weblog/2009/09/something-sidewinder-related.html.

The manner in which the seals are created for the Sidewinder P/T/Z camera is the same manner in which the seals are created for the all fixed cameras manufactured by WTI. A sealed outdoor camera (from WTI) meets the same core purpose as that of a pressurized camera; contaminants are prevented from entry.

Consider the maintenance cost reduction benefit of a sealed camera: no pressure checks! (Also, no alarm conditions when internal camera pressure drops)

Consider the installation site. Underwater (sea floor monitoring) or extreme altitudes (weather balloon) will indeed require some type of pressurized camera enclosure. Highways, intersections, utility infrastructure sites, building perimeter, etc… Why have pressurized cameras?

~David Scales, C.T.O.

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WTI (Wireless Technology, Inc.)

Video Surveillance Products Dedicated to the Broadcast, Global Security and Transportation Markets!

www.gotowti.com ● www.wirelesstech.com

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Wireless System Installation Tips

When selecting a location for your WTI wireless video systems, there are a few important things you need to take into consideration.


1.) Line-of-Sight (LoS)

To achieve optimal performance, from any high frequency wireless device, a clear line-of-sight is necessary. Line-of-sight refers to a clear, unobstructed path between the transmitter and receiver antennas. The antennas produce an invisible beam that can be compromised by building obstructions, ground and/or water reflection. Well designed RF products can withstand a 20% loss of this invisible beam before performance reduction is detectable.

To get the best possible signal with your WTI wireless system, you need to have LoS or transmit through the least amount of materials on the peripheral of the LoS. Problems will occur when you try to transmit through any type of metal or steel-reinforced concrete. If there is a significant amount of metal too close to the transmitter antenna, reflected RF may cancel some of the transmitted signal and reduce the range and the quality of the signal. For maximum radio frequency (RF) propagation, a clear LoS is best.


2.) Antenna Height

Antenna height and line-of-sight usually go hand in hand, though not always. Many times LoS is achieved but the consideration that traffic may pass through the RF path is not always thought through. This scenario occurs often at truck depots, airports and shipyard installations. Mounting the antennas above traffic not only eliminates intermittent signal loss it also helps a link achieve optimal performance. By mounting the antennas as high as possible it will allow the link to operate in air space that is less crowded with other RF noise. Mounting the antennas above other RF noise gives the receiver less to contend with by allowing it to hear the information it has transmitted more clearly, therefore processing that information more efficiently and accurately. The bottom line: make sure that your wireless system will be mounted high enough to prevent traffic from passing between the transmitter and receiver. If the system is placed too low, the quality of the signal will be reduced every time a large object passes between the two antennas.



3.) Antenna Mounting

Make sure that each system antenna is mounted to a solid structure that does not allow for antenna movement during strong winds. Although WTI’s antenna design allows for small movements this tolerance lessens the further the RF signal must be propagated. A 30° movement on our 2 mile links with our patented phase array antenna would not affect the signal very much but the same movement on a 50 mile link could miss its target by miles. That being said: please keep in mind that our product mounting requirements dwarf when compared to the monstrous and rigorous concrete and steel mounting required for super higher frequency microwave, a simple solid pole will do.


4.) Testing

It is good practice to bench test your WTI system before installation. Even though WTI is an ISO 9001:2000 certified company with a strict quality control processes, equipment can be damaged during shipping or a miscommunication to what was ordered could take place. This is why the equipment should be tested at the shop. Bench testing allows for confirmation that the correct equipment was shipped, that it works properly, and it builds confidence in the overall system operation before the permanent installation.

We’re not done yet! Before permanently mounting the system, we also recommend testing the system at the site where it will be permanently mounted. This will ensure that the system is working properly at that site and not affect by other RF that may be in the area.



These are just a few basic things that can be done to ensure a working installation. By following these tips we hope to reduce and/or eliminate the risk of your installation exceeding its estimated time and cost. WTI’s products are designed for easy installation and we understand the temptation to just put it up and let it ROCK but its always good practice to test before hand. In the long run this will save you money!



Here are two forms to help you plan your next WTI (Wireless Technology, Inc.) wireless system installation.

Wireless Application:
http://www.gotowti.com/Info/WTI_WirelessSiteSurveyForm.pdf

Ethernet/IP Application:
http://www.gotowti.com/Info/WTI_EthernetSiteSurvey.pdf



~Eric Myers, Director of Wireless Products