Lightning Sensor


Thread Starter



I've been looking at product selections of lightning detectors and they all seem to be prebuilt packages that have fancy displays and HMi that are used to interface the user interface that they have prebuilt. I am trying to find a single sensor that can detect lightning within X miles from the sensor. I am needing it to be something that I can take into my PLC (SCADAPACK), so RS485/232, 0-20mA, 0-5V, Modbus, are all on the table. I'm needing to do some logic on my PLC side when there is lightning in the area and I am having trouble finding any sensor that is even close to the specs that I am needing.

Has anyone ever used or know of any sensors that can detect lightning in a given radius of the sensor that I could take into a PLC?

Curt Wuollet

Detecting lightning within a defined radius might be a problem. Not detecting the lightning, that's easy. Defining the radius is a little harder as lightning events happen in different sizes and generate more or less signal. You can detect lightning with a FET set up as an electrometer, a simple RC circuit will extend the pulse long enough for a PLC input. A network would be way overkill for one bit. You could count pulses in an interval to judge how near I suppose. You don't really need a remote, lightning is generally powerful enough that the signal is just as good at your PLC. Using a loop of wire from input to ground will reject light hash and the usual "normal" noise events, but will lower the sensitivity.


Lynn August Linse

I think this also depends on your goal. I'd assume the normal 'lightning' system is some form of optical processor and an embedded PC-class number cruncher. So they will be neither cheap, nor worry-free.

If you just want to 'prove' to the customer that the burned out device was from lightning, I suppose you could run a ground wire out to a stake 100 feet out side of the control run, then have an appropriate fuse in the line. If the fuse blows, it means you had a ground-potential difference larger than "X" at the control room.

Lightning protection is not hard - just takes cash & understanding, plus any isolation you add to comms or analog loops helps.

Lynn August Linse

Actually, the vaisala dot com website was pretty interesting. Although it would be tough to interface to a PLC (but maybe not SCADA/HMI/OI panel), they also offer internet access to real-time lightning records, web service calls and such.

If the goal is to keep workers from climbing things during lightning, they may have a smart-phone notification service. If the goal is to shut down production, then such an external link may not be reliable enough.
This is an interesting message thread and somewhat related to one 14-year client that makes (and maintains) tornado warning sirens (for cities, counties, and nuclear power plants).

As you mentioned Lynn the Internet is not considered a reliable method of communication.

What we might need most (for weather warnings) is a new weather radio system that has data capability, but (from what I remember) this is not being implemented. Large radio and TV stations with diesel backup power with data on a subcarrier is being used a little some places (see emergency broadcast systems for more info).