Security and surveillance need to be effective anytime of the year, even when it is very cold, dark and humid. Optex detectors are designed to work reliably in both summer and cold winter conditions thanks to a range of built-in capabilities such as intelligent detection systems and quality components.

    Optex house driveway in winter residential image

    For example, our REDWALL SIP outdoor series feature an intelligent PIR detection system that can detect ambient temperature and illumination and automatically adjust the sensitivity for optimal performance. In addition, all our dual-tech sensors are designed with a Ceramic PCB material and gold-plated antenna, which ensures longevity if they are exposed to condensation during winter in non-air-conditioned facilities.

    However, for some sensors, our tech team also recommends the use of accessories and adjusting settings to ensure best performance.

    Automatic Gain Control Circuit and Automatic Transmit Power Control for IR beams

    The SL Series and AX Series beam detectors monitor gradual changes in signal strength due to the weather and can adjust the sensitivity to maintain stable signal strength. In extreme weather, the beam detectors will generate D.Q output (environmental disqualification) to alert if the weather is affecting the lower performance of the sensors. To check the D.Q environmental trouble is working, the best way is to cover the beam with a plastic bag and see if the ‘trouble’ output has been triggered.

    If the intrusion system is using an alarm panel, ensure the sensor’s D.Q circuit is physically or wirelessly connected to the panel so it can generate an alert.

    Environmental resistance setting in REDSCAN LiDARs

    The REDSCAN Pro and REDSCAN Mini-series have an environmental resistance setting which should be enabled to improve performance in extreme weather conditions e.g. snow, fog and heavy rain.

    Environmental resistance has three options are available:

    • [Disable] Response time if alarms are minimum but false alarms can increase in harsh environment such as fog and snow.
    • [ Enable ] (Default) False alarm due to a fog or snow can be reduced with balanced high detection ability.
    • [ Enhanced ] Reduction of erroneous reports due to a fog or snow can be maximized. It may result in a longer response time

    Extreme Weather accessories


    Most OPTEX detectors will function normally up to -20 and -25 degree Celsius. If the temperatures drops lower than that and in areas prone to frost, there are a number of sensors which can be fitted with heaters, enabling them to operate in extreme cold weather.

    RLS-LWVH heated lens for REDSCAN Pro

    With this simple accessory REDSCAN Pro can operate down to temperatures of -40 degree Celsius. The replacement window with heater unit is suitable for both RLS-50100V and RLS-3060V and can be ordered as an optional accessory.

    SIP-HU heater for SIP series

    Heating unit suitable for all REDWALL SIP models, to be used when the temperature is lower than -20 degrees Celsius and allows normal operation of the sensor down to -40 degrees. Once installed, it will be on constantly. You can check the heater is working by checking the power consumption.

    HU-3 Heater for IR beams

    Heating unit for all hardwired models of the AX and SL Series. When installed the heater will always be on. To check if the heater is working properly before the temperature drops, the best way is to check the power consumption.

    The heaters HU-3 comes in a pack of two units. For the short-range AX beams, one pack suffices for the pair of beams. For the long-range SL infrared beams, it is recommended to have two heaters in each beam (one at the top and one at the bottom) so two HU-3 should be ordered.

    TWH Non-polarity heater for beam towers

    OPTEX Dual and Quad IR beams can be installed in towers and can be equipped with heaters and thermostats to prevent any risk of frost.

    The thermostat will only action the heater when needed. To test it is working properly, use the Thermostat test switch. Available in 12V or 24V, 250mA.

    Please note that heaters cannot be fitted in battery-powered beams, as the power provided by the batteries isn’t enough.

    Hoods for rain and snow

    SIP- MINI Hood and SIP-MID Hood are metallic hoods that fit on top of the SIP sensor to avoid snow accumulating on the PIR.

    • SIP Mini-hood: for the SIP-3020/404/4010 series and SIP-3020/404/4010-IP-Box
    • SIP Mid-hood: for the SIP-5010/100 and SIP5010/100-IP-box

    Preparing for winter checklist:

    Getting ready in advance: important considerations when installing sensors

    1. During installation, the detectors’ mount screws, gland plugs and rubber seals must be used to stop water ingress.
    2. Where gland is used for wire and cable connection to the device and cabinet, aim to have the gland facing down. (See image below of SIP3020 and RLS2020I as as an example)
    Optex glands tech tip

    During winter weather conditions

    1. Following heavy snow: inspect and remove snow collected on the detector, especially the lens.
    2. Inspecting the sensor: open the detector cover when it is dry, do not open the cover in rain. Use an umbrella if it is absolutely necessary to open the cover in the rain to avoid moisture inside the detector.
    3. Cleaning the detector lens: If the lens of any of our sensors are soiled or dirty, it may affect their performance. The cleaner the lens, the better the performance. If there is mud or dirt on your OPTEX sensor’s lens, it should be cleaned. The best way to clean it is with a soft cloth and water, or with antistatic foam cleaner. Detergents shouldn’t be used as they can deteriorate the quality of the lens.
    4. Cleaning the IR beam cover: Salt, mud and grit can sit on the beam cover and affect the detection performance, it is recommended to clean the cover with a damp cloth.