electricity usage data logger

Keith D said the following on 25/07/2006 21:47:

It has a sensor that you connect around the live wire of your meter tails that measures the current flowing in the wire. The sensor transmits the signal to the receiver (as shown in the photographs on the above website) and the receiver (which you programme for the nominal voltage of the mains) then calculates the power being consumed by the whole house. This is an instantaneous (or maybe average) reading and the unit does not appear to do any data logging at all.

See here:

I would consider using one of these: -

interface so I

I have a secondary elctricity meter (that was originally a coin operated one) that has had the coin mech taken out and a slotted LED sensor put on the disk, which via an optoisolator drives the interupt bit of the parallel port. I've been logging electricity (and water too) using this method for over 10 years now.

AWEM

Interesting. One interrupt per revolution of the disk?

electricity

interupt

Yes, and I use a simple RS transducer to give me water rate usage, though that has to have a 'divide by 100' circuit in series due to the rapid rate of revolution. The software (which I wrote) does simple zone control on my central heating, and also has provision to monitor gas, but I've never found a suitable sensor.

AWEM

Could you rig up an optical sensor that looked directly at the digits on the companies gas meter. It wouldn't have to actually read the numbers, it could just log movement of the last digit (thinking of my gas meter that has an 'odometer' type display)? Although thinking about it a webcam with character recognition could take periodic snapshots of the gas meter

Andy

message

being

slotted

monitor

digits on the

I held back from that approach as it could scare the pants off meter readers ! The normal gas meter 'breathes' with a bellows, and can be distinctly heard. I had indended to make a microphone based system with filters to pick out it's distinctive sound, but like so many things never got round to it.

AWEM

If you used a laser mounted on the wall opposite the meter the meter reader should only notice a small burning sensation if he keeps his head still for more than a minute!

Andy

Here you go!

Here's a potential solution costing just a couple of quid...

interface so I

electricity used?

But the problem with both that gas interface and opto electricity interface is that they invite too many questions from the meter readers - I'm sure that you'll be reported for possible fiddling attempts with bits stuck all over the meter. That's why I opted for a separate meter that I modified in series with the boards meter.

AWEM

I can't even remember the last time we actually had someone round to read our meters... Even so, it'd be trivial to pull the blu-tack blob holding the sensor off the meter for the meter read so I really don't see this as a significant disadvantage, particularly in the context of the simplicity and low cost.

Mathew

Me neither - especially as the meter readers don't work directly for the supplier and are unlikely to be arsed to do anything about it even if they did suspect foul play. Besides, the seals would still be intact so even a jobsworth would have little reason for suspicion.

LOL

OK. Do you remember which one?

If what you put on the meter is no more than a photocell /phototransistor on end of cable, this minimises the suspicions. Put the circuitry on it there too raises more question marks.

In the time I've been here I dont think theyve ever even seen the meter, they dont seem interested now.

NT

monitor

RS part number 257-133 - amazingly still available at about 20 squid

AWEM

Thanks for that. At 15mm, doesn't it affect the delivered pressure/flow, or isn't that a problem?

My gas meter, an R5, has one built in, and a socket on it labelled 12V 10mA max, 1 pulse = 1 cu ft.

The socket has a blanking plug in it, with no obvious way to get it out, and I would need to find the plug to fit it too.

usage,

As it's a 1/2" lead pipe coming in I don't think so

AWEM