Wireless Gas/Electric Meters

They just tweet out the reading. It is not like the gas meter is spewing out continuous data. So the power of "duty factor" and long life lithium gives them long operating life.

That was the explanation I read when we first got them. The electric meter has an easier time. ;-) I think the electric meter is around

1.2GHz or so. I see something pinging out there on the spectrum analyzer.

It's 2-way so it can't sleep *too* deeply. I suppose it could wake up every week or so and when phoning home ask if there's anything it's supposed to so (upgrade firmware shut off gas etc...) rather than being on constant standby to receive.

It's interesting to note that the meter still seems to be analog cogs and sprockets on the dials. I wonder how/when that gets translated into digital.

-sw

Good Lithium Thionyl Chloride battery, low self-discharge, low duty cycle, and low power consumption:

I see it has a FCC ID on it. I'll have to see if my meters have FCC ID numbers visible to the outside world.

So the Star meter is one way, that is no receiver. In general, that isn't a good scheme. ACK is your friend.

They do. Locally, PG&E uses Silver Springs smartmeters:

PG&E?s electric SmartMeters operate in the 902-928 MHz frequency-band to communicate customer electricity-usage to PG&E. PG&E?s gas SmartMeters operate in the 450-470 MHz frequency-band to communicate customer gas-usage to PG&E.

The 900MHz stuff is spread spectrum. The 450MHz is NBFM.

SmartMeters communicate intermittently, with each RF-signal typically lasting from 2 to 20 milliseconds. These intermittent signals total, on average, 45 seconds per day. For the other 23 hours and 59 minutes of the day, the meter is not transmitting any RF.

I pointed a yagi antenna at my electric power meter, and threw together an RF amp, filter, detector, and data logger to see how often it really transmitted. I'm rather far away from the network node, so mine only belched bursts of RF 1-3 times per day. However, when I did the same at a customers location, closer to the node, the store and forward traffic was substantial, resulting in 20-50 transmissions per day. I screwed up and didn't log the total transmission time per day, only the number of transmission bursts. It is my understanding (possibly wrong) that the battery life is calculated on the basis of one bursty transmission per day and might be rather optimistic.

I gave a short talk on the alleged RF hazards of smartmeters to a rather hostile audience a few months ago. I'm still recovering, so no more questions about biological RF effects please. Just read the RF FAQ above.

Now, go away. It's Ham Radio Field Day weekend and I'm somewhat busy.

That's a lot of communicating of pretty boring data, IMO.

We expected no less.

And I was being pessimistic thinking maybe it wakes up every week.

Don't forget your decked-out helmet.

Cheers :-)

-sw

Data is boring. However, when enough data has been accumulated and massaged, it becomes information, which is far from boring and often quite valuable.

45 seconds per day is 273 minutes per year. That's about half my cell phone use in one month.

Over the 20 year life of the meter, you would be exposed to about 91 hours of RF, which certainly qualifies as useless information.

If you're really worried about RF exposure, I suggest gifting with orgonite. That should also keep you busy for a while:

I won a free dinner because if this test and a few others I threw together. I was also thinking of making a "Smartmeter Meter" that would detect and log emissions from smartmeters. There are plenty of paranoids out there with money.

I'm able to download hourly electric usage from my house. Here's a sample screen for 3 days ago:

The big peak is my morning use of the bathroom electric wall heater. I can also download monthly CSV and XML data since June 2008. What's a little brain cancer when you can obtain such nifty data?

The one with mouse ears or the propeller on top? I brought my aluminum foil wrapped plastic helmet (with the ear muffs for chain saw work), but nobody was interested in taking my photo. Sniff...