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 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!

The product has been packed as a typical cheap Chinese stuff, so the first impression was sad. But practically it works well. Instruction included is so detailed, that I have fallen asleep reading it. Installation process is easy enough - just sticked to the wall in the right position. When I firstly set it to sensitive mode - it was ringing every hour (I live in an old apartment house, so probably it's shaking a little bit every time when someone shuts the door, or jumps) - such sensitive mode is not for me. After that I lowered down sensitivity to medium level. So, now it only rings when there is a real earthquake. In practice - it doesn't predict it now, and even gives a signal with 2 seconds latency (I feel earthquake myself, and then hear the signal). It would be probably more useful in more still / solid, maybe separate house. But in my case the only useful thing - is that it will definitely notify me about earthquake when I won't notice it for some reasons (will be sleeping for example). And in case of severe earthquake- every second can be important.

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).

This alarm is fine and helps a lot at night. I live in a very seismic area so I need some kind of alert for earthquakes after having a 7.6 magnitude last year. The device is really simple and honestly now I don't buy the wave marketing thing that these people have. There's a simple reason for this, the sub-woofer in my room can activate it when playing at high volumes. This is a great sub-woofer but only 8" and 100 watts. The sensitivity was set to "high" but not "very high", this ruined the experience for me. If I had the chance to go back in time I wouldn't buy it again, it's simply too expensive for what it does. Another thing to consider is that it doesn't have an off button. This makes moving the alarm or swapping the battery very tricky.

This alarm has a simple design, and works, but it must be installed smartly, and needs to be set with some care. attach this alarm to the most solid beam that is extremely well connected to the ground. This is the only way the device can effective receive the quake signal. Instead of satelite signal, it needs to receive an early vibration from the ground. Once you've chosed the best beam, and installed the alarm, set you sensitivity as light as you can without it sounding. (Adjusting the dial can be fidgety, so be patient.) Then once stable, try jumping up and down, & slamming room doors and cabinet doors ... if any of these vibrations set off the alarm, turn down the sensitivity in small increments. (Be aware, even street traffic could set if off.) once stable, you should be good to go. I kept my battery exposed for several months, in case the garbage truck or vibrations from my apartment neighbors could affect the alarm. I could shut it off quickly by disconnecting the battery. Hope this explanation is of some value. I took time to install and fine-tune as written above, and mine does not fail me.

I received the product on time and in good condition. This product could be improved greatly with an on/off switch and a few adjustment knobs. There is only a screw to adjust sensitivity. One of the units I received had the needle hanging outside the triangle and when I finally jiggled it back into the triangle it was not perfectly vertical. 2 knobs for horizontal axis adjustment would be a big help. Also I had to mount it on a slant and pad the lower portion of the unit in order to get it to be centered. The alarm tends to go off while installing the battery which is very annoying. An on/off switch would be a big help. We have not had an earthquake yet so I cannot review its effectiveness or usefulness. Some wind chimes in the house might be equally as useful.