Chamberlain Cwpir Weatherproof Outdoor And Alert System Add-On Sensor, Includes 1 Sensor

I had some concern after reading some of the reviews but went ahead with this purchase anyway. I'm glad I did, it works well. For the benefit of others, here are some of my notes.The reviews that talk about heat and partial detection are correct, placement and aiming is really important. I installed these at the end of a driveway that runs east-west in an open field, so road traffic and the sun were factors. I placed two units, one each on opposite sides of the driveway, facing towards the driveway at about a 45 degree angle away from the road. Each unit was secured to a tree about 18" off the ground. I placed two opposing units because for one, I was concerned about reliability based on some reviews, and two, on cold days it does need to see something hot so I wanted to capture exhaust heat regardless of where it was placed on the vehicle.Each sensor is placed approximately 12-15 feet from the driveway, which is about 12' wide itself. This seemed to be the perfect placement; movement anywhere on the driveway activates both sensors; if you get a few fee off the driveway it only activates the nearest sensor.So far this has a 100% accuracy rate. I haven't had any confirmed false alarms; out of the handful of non-vehicle alerts we've had, a few were confirmed to be deer or dogs and others just couldn't be confirmed in the darkness. It does pick up humans; it had no problem detecting me walking down the driveway on hot days nor when I was thoroughly bundled up from head to toe on cold days. I've had no issues with the sun nor passing road traffic interfering with the sensors.The sensors have a green LED that activates and is visible through the PIR lens for about 1 second when they detect motion. It's usually not a big deal, but on a dark night while driving towards the sensors the green light stands out and quickly draws attention to the unit. If you're going for a covert installation, keep this in mind.A previous homeowner had one of these units installed very near where I installed my new units. It showed signs of corrosion, and based on other reviews I agree that water intrusion seems to be an issue. So, when I assembled my units (yes, some basic assembly is required but its not rocket science), I used clear silicone to make a good seal around the face plate, including the antenna hole and screw holes. I installed the included sun/rain shade above the units too. When I change the batteries next time I'll see how they're doing at keeping weather and bugs out. I wish I'd had some Lithium AA batteries to use when I assembled these; instead I had only alkaline batteries on hand. I'll hopefully provide an update here on how long the batteries lasted and how well they're keeping dry.The mounting plate worked well, I pre-assembled everything and just screwed the mounting plates directly to trees near the driveway using deck screws.Reception so far is good. These 2 units are placed right at 100 yards from the residence, across an open field with no obstructions aside from a few small ornamental trees. The signal then has to pass through concrete siding and 4 interior gypsum walls. The beep is loud enough (at high volume) to be heard throughout the house, even on other floors. Pairing the units with the receiver was easy enough.Things I wish were different on these:The beep when a sensor activates is a long sort of whiny squeal versus a quick chirp, and its a little irritating. Not necessarily bad for an alert, but it happens to closely mimic the washer and dryer beeps. Each sensor that is paired with the receiver gets a corresponding number of beeps. With 8 units, that's an awfully long series of irritating beeps.It would be great if the alert beeps could be adjusted (pitch of tone and length of the beep).It would be good if there was an aux output (dry relay contact) built in to the unit so this could be tied to a variety of other systems. Even better would be 8 discreet relay contacts (one for each sensor). Best would be throwing in a Z-Wave or similar smart module so you could really integrate this with other systems.With a simple sequential beep for the sensor zone number (1 beep for zone 1, 2 beeps for zone 2, etc), you run into some problems. For example, if sensors 1 and 2 activate at nearly the same time, you get 3 beeps. Well, was that sensors 1 $ 2 going off, or sensor 3? Did sensor 4 activate or was that sensor 2 twice? You get the idea. If the sensors had a unique beep pattern (for example, a high pitched tone followed by a number of low pitch tones for each sensor) it would be easier to distinguish the different sensors. In this case 'hi-low-hi-low-low' would easily be distinguishable as sensors 1&2 versus the 'hi-low-low-low' of sensor #3. The point is, the current system can be confusing across zones and there are many answers to this problem, but the manufacturer should pick one and implement it.

I have been researching driveway monitors for nearly two years, after my first system failed by producing false and no alerts. Most systems' reviews complained of very short range, alert errors or very short life. Hence, I delayed my purchase, occasionally looking for new products on the market.Recently I visited a friend's house and noted that he had an alarm. He reported that he rarely has a false alarm (which could actually be a deer crossing the drive.) Also, the sensor and base are quite a distance apart. He reported complete satisfaction with it, especially he cannot see cars coming down his driveway from his house. He must go into the garage to see anything.Hence I decided to give this one a try. I ordered the base/sensor package and an extra sensor. The setup was extremely easy. My biggest challenge was to figure out how to attach the unit to a tree trunk. A small piece of 1/2 x 4 x 10 scrap lumber provided me a flat mounting base, which allowed me flexibility in locating the screws to attach the board to the tree trunk. I fired up the unit, using full range and most sensitive settings. It works perfectly at about 150'.I ordered the extra sensor, in case the first one did not work. So with the first one working well, I decided to mount the second one about 500' away. It seemed to work well - for awhile. Then it started falseing almost continuously with short periods of silence. Well, a trip to the sensor with a weed whip, clearing about a dozen tall grassy plant stems, the falses disappeared. The unit is so sensitive, it was picking up the movement of the grasses in the breeze.To date I have only had two falses - one about 3 in the morning which I suspect was a deer who roams our land. The second was daytime with the other sensor. No apparent reason, perhaps another large animal. There is an advantage to two sensors. If only one sounds an alert, it is probably a false, since someone on the driveway should trigger both sensors. Which brings me to a third glitch. We did have one occasion where a car tripped the first sensor, but not the second.The system has been in operation now for three weeks and I cannot wish for better operations. I have just purchased two more sensors.UPDATE 8/22/14We have confirmed that the "falses" are a doe and her two fawns. They've found a sweet spot to graze near the sensor.UPDATE 12/6/2016After being in operation over two years, the sensors are working just fine. I'm truly amazed and highly satisfied. Given the severity of our winters here, I usually pre-emptivly change the batteries in the late Fall, to avoid having to navigate snowdrifts when a battery fails in February. Also using lithium batteries works out well during the cold months, as their output is not affected by the low temps.

This is my third alarm and we love it. I get the sound alert within 10 seconds of someone stepping into the area of where the alarms are situated. Best sound alarm going!

This is my 2nd one so I hear 2 beeps in stead of one. Easy to connect and install.

Worked OK for a while - however they deteriorate very quickly in the weather. Poor quality plastic housing.

Works well, even detects a spider that crossed the sensor.

great range, have it in my trailer about 100 ft away, works great