JDSc-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>

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.