JDS c-88quake Earthquake Alarm

This Earthquake Alarm is very reliable once you install it properly. Yes, it requires calibration, and it will take some time to get it working fine, specially if you are not in an active seismic zone. I have installed it in México City, and after a month I have detected quakes located as far as El Salvador. The alarm generates a loud but not annoying sound. Since it works using a pendulum located inside a triangle acting as a limit that when touched it will sound. This alarm detects the p-waves which travel faster than the destructive s-waves, thus this alarm will sound before the quake and sometimes you will not even feel it because it is so far or too weak. How many seconds before, depends on how near or far you are from the epicenter. Mexico city is a seismic area and the idea was to detect those quakes at 250 miles away where the faults are located, right in the pacific ocean or in Oaxaca. We also have the Popocatepetl Volcano and so far there has been no activity there, so I still have to wait for some activity. You will learn how far or how strong a quake is by the way it sounds, and you can act accordingly. For instance, a quake located at El Salvador (1000 miles away and magnitude 7) will only do a couple of pings in a one second period, while one located at 300 miles at magnitude 5 will sound with some long and short pings during period of 6 seconds. I guess that a magnitude 7 in such area will generate a steady sound for at least 10 seconds. Since almost every day makes a sound, my family try to guess how far and how strong the quake is. A quake is no fun, but science is as we are learning how the earth works and how events that are located very far affect where we live. With this device there are really no false alarms, you may jump next to the alarm and it will simply stay quiet, even though I have set it to be very sensitive (locating the pendulum very close to the triangle). To verify everything I have subscribed to the earthquake notification service at [...] via email and that way you can receive the quake information promptly and associate the pings in your alarm to the magnitude of the quake. Now when it sounds, I take note of the hour and the sound generated by the alarm, after that I usually receive an email in a few minutes with the details. This is a must if you live in seismic active zone, like California, or Chile. Knowing in advance that a quake is coming could save your life. The bad news is that if you live right at the epicenter or where a fault is, there is no enough time to get a warning. The pendulum works by moving at the presence of p-waves, specially those coming from the sides than below. <spanish>Si vives o trabajas en la Col. Roma o en el Centro de la ciudad y especialmente en algún edificio, no lo pienses, este aparato es para ti</spanish>

5-stars for an affordable shaky toy. Likes: Affordable, long battery life, works. Dislikes: The velcro issue, but I resolved the falling off the wall issue by leaving the battery cover off, then run a long but small/narrow screw through the small opening in the battery compartment that's slotted to the battery cover, then I just set the battery somewhat in the battery compartment without the battery cover. Never falls off the wall now. Add: I placed a couple dots on the sensitivity adjustment knob with a sharpie to aid the few weeks it took me to get the sensitivity adjusted by having the dots provide a somewhat reference, since the knob is small and stiff, I could reference approximate if I didn't get some turn or overshot what I was trying. Living in California, but not in the more major fault/active areas (Sacramento), my area does get some shakes on occasion mostly from the more active areas with larger magnitude quakes. I have it adjusted now that with the occasional dinging, I can confirm quakes online - when (time), where (location) and magnitude, for more near active areas. At first I had it set too sensitive and I think maybe a little settling of the home caused dinging. I should attach one to the fridge and another to the microwave just to annoy the wife when she slams the doors. Note: I have two little doggies. When it dings, one runs to the far side of the home, other barks. The barker aids letting me know if I'm sleeping because I have the quake alarm on the other end of the house from the bedroom. I can hear it (it's facing toward & down the hallway) but the barker goes off immediately and I have to tell her "okay okay" to turn her barker off. So if in a deep sleep, she ensures I'm going to know if the ding'r goes dinging. Living in an quake active state, what's not to like about it. one can never have to many toys - er my wife thinks otherwise.

This is a simple alarm that detects vibrations, especially those caused by earthquakes. It's a simple but effective mechanical design in which a brass rod/pendulum hangs freely and if subjected to large enough motions/vibrations, it will touch the sides of the brass V-notch/triangle around it (see my review pics). This will trigger the alarm circuit to sound. The alarm is a loud, metallic 'dinggggggg' chime sound which gradually fades out a few seconds after the last vibration. In a real earthquake with constant vibrations for many seconds or more, it makes more or less a solid chime sound until the vibrations stop. The alarm volume is not adjustable, it's always loud. Considering this is an emergency (possibly life-saving) device, maybe that's not a bad thing. Nonetheless, I find it too loud and would prefer to have adjustable volume. You can mount it on a wood or steel stud wall, but you'll have to turn down the sensitivity to avoid constant false alarms from vibrations caused by the occupants (slamming doors, stomping feet, etc.). To be able to be used at high sensitivity settings, it has to be mounted on a solid concrete wall. The unit should be mounted perfectly plumb (straight up & down) but it will still work if it's not exactly plumb. The velcro mounting strips allow re-positioning until you get it right, but velcro is a crappy mounting scheme. The sensitivity is adjusted by turning the white plastic screw on the front, which increases or decreases the clearance between the the pendulum rod and the V-notch. For high sensitivity, you'll have to have the pendulum resting literally about a hair away from the edges of the V-notch. To test that it's properly set up (both the mounting orientation and the sensitivity setting), lightly touch the unit - the alarm should sound (see my review video). At very high sensitivity settings, even large trucks driving by might trigger it. This might be an annoyance - but it means it is working. The big question: does it work? Yes - if it's set up properly. One morning it was going off for about 15 seconds in the basement even though I couldn't feel anything sitting on the floor above. The next day, the local news reported a magnitude 4.1 earthquake 135km (84 miles) away at the exact time it went off.

This alarm is simple in design with little to go wrong. It works very well, detecting the P waves of an earthquake that race ahead of the damaging S waves, giving you seconds of early warning to take cover. The further away the epicenter of the quake, the more warning time you receive. The alarm sound is very distinct, so it breaks through the ‘this can’t be happening’ mental fog so you can take cover sooner. The unit doesn’t use any power from the 9 volt battery unless it is alarming, so the battery will last for two years or more. It has adjustable sensitivity so you can tune out minor quakes while still allowing warning alarms for important quakes. Don’t let the low price turn you off - this is a well made unit that uses a simple mechanism to reliably detect the early warning P waves of earthquakes. Some years ago I had one of these in my home in Georgia. I was awakened about 5am by the alarm pinging, but the earthquake shaking never came...the epicenter of the quake was more than 170 miles away in Tennessee!

First off let me start by saying I live in south-central Illinois far from California who experiences earthquakes on an everyday basis. How ever we have a fault system located here know as the New Madrid Fault System which branches off in to several faults which the closest one to us is the Wabash Valley Fault Line. (About 60 miles away) The New Madrid Fault System was repsonsible for the biggest earthquakes in history back in 1811-1812 in and around New Madrid Missouri and was widely felt over 500 miles. They keep saying we are due for at least a 6.0 to 7.5 earthquake within the next 50 years. In the last 10 years alone we have more earthquakes with atleast a magnitued 3.5 or bigger on the Wabsash Valley Fault than they have had on the New Madrid Fault itself and alot of people feel the Wabash Valley Fault will be the one to produce the big one and maybe not the New Madrid Fault As there is evidence in the creek beds of atleast 8 earthquakes in history that have been estimated about 6.0 to about 7.0 in magnitude. In April of 2008 we had a 5.2 magnitude earthquake with many aftershocks that was nothing like I ever had felt before and I then said I hope we never have anymore. Well last night we had a 3.7 magnitued earthquake and I said enough was enough and that I may not have any warning to get to safety especially living in an apartment building on an upper floor. I had heard about the earthquake alarm and its reliabilty to sound an alarm before an earthquake and have been always wanting to get one of these but was reluctant. Well I finally did yesterday! As soon as I recieve it I will hang it up and hope that nothing ever happens but I know based on reviews and studies this alram has/had recieved that this thing actually works. I will test the theory and update my posting here when the next earthquake happens which I hope will never be the case but just incase I will be ready. Its always good to prepare because a few seconds could mean life or death. I suggest anyone living in an earthquake prone area to get one of these as it could be your only life saver during an Earthquake.

I was disappointed to see the device is built like a toy. It has a cheap plastic case, metal bar that swings back and forth, and Velcro for attaching to your wall. I was hoping for a little better construction. Definitely would have expected a better way to attach this to a wall than to use Velcro. I stuck it to my dining room wall and it appeared firmly attached. Several months later I'm awaken by high pitch noise and come to find that the glue on both Velcro strips has detached itself from the wall. Since there are no holes for attaching with screws, I'm going to drill my own hole inside the top battery location and screw this to the wall. If this ever does give an early detection of a quake, I'll increase the number of stars. Update 9/16/12: No earthquake to test it yet, which I'm glad to say! I agree with the comment about the design being built to carry out it's function with the fewest parts and simple layout. There is less chance this kind of system will fail when the day comes that I need it to work. I was able to stick it to a wall using double sided tape and it hasn't fallen since. I added one more star to the review and changed the review title. I'll definitely increase the number of stars after I see it work.

I have had one of these installed in San Francisco. There is about 10-30 seconds warning, depending on your distance from the earthquake. It works great. This is a completely *analog device* using an inverse pendulum. The electrical circuit is exactly like the board game Operation, in which the metal bar makes contact with a metal plate surrounding the pendulum. This sounds a beeper powered by the 9V battery. It also draws no power when it is not operating, making the device last as long as the battery's shelf life. While incredibly simple, it can be remarkably sensitive if the knob is not adjusted properly. A semi truck making daily early morning deliveries half a block away would routinely set the device off until i properly tuned the sensitivity. Leave it and forget once you find the right sweet spot. One very important thing to note is where to position the device. Find a solid exterior wall. Also, come up with your own mounting system, as the provided "mounting hardware" is a joke. Both of the ones i purchased fell off several months later... Now, lets just say that a beeping is simply not enough for you. You can easily connect this device to an Arduino using a second 9V battery connector, and connect it to a computer to send text messages or tweets: [...] Or, if you want to write your own code, just connect one of the 9V battery connector wires to ground, and another to an Arduino GPIO (be sure to configure a pull up).

We started getting some quakes at near where I live. In Texas. I got one device and has sound the alarm twice. With 3.6 and 5.4 magnitude. It has a Pendulum, if this moves and touches a side, it will activate. The alarm only works while moving. When installing make sure the Pendulum is in the center.