Sonic watchman oil gauge?

Mine does not. I have dogs for that.

But again, the ultrasonics might be no more than a piezo click and an ceramic mic. If the pulse duration is short its very low average power - even if its a milliwatt peak. Likewise the radio transmission - what a

Its the old principle of using high peak to mean ratios to lower power consumption because you only have a very limited data rate.

The answer being it only sends intermittently. Very intermittently.

I have three heating tanks, each with a Watchman, and the 'special batteries' in each case are AA cells stacked in a length of 15 mm copper pipe and soldered to (I think) and F type connector. Careful cutting of the pipe allows replacement, and a slip coupler compression joint completes the job.

AWEM

Mine has a lithium coin cell in it...

well if you want another of those with a dead battery say so

I decided I couldnt be arsed and a new watchman with a ten year battery was almost as cheap as a new battery for one of those...

I have got the opposite gauge says full and I know it's half empty

Cobweb or something else obstructing the sensor path?

My old sight glass was way more unreliable.

Did you find out why it was saying full when half empty? Having same problem at moment.

replying to The Natural Philosopher, bootman wrote: Our sonic watchman always reads full

Probably because the installer didn't drill a hole in the tank before fitting the sensor.

Interstingly enough I ended up buying a new one but it has not been 100% relaible.

First of all it went on slightly on te skew and didnt work. I thne took it out and suspneded it over the kitchen floor to sestablish it di sort of work at 3 foot range frim te reveiver.

So I replaved the mounting plates as well.

Having got it exactly square to the oil surface - or as near as can be done with a tank that slopes slightly - it now monitors oil level; correctly , when it works at all.

I have found the one socket in the kichen (curiously close to te TV socket thats sits behid a broadband amp that boosts everytng from

Frankly its crap compatred to the older ones with the captaitance sensors.

And a proper aerial.

- Its hyper critical on installation angle

- its very poorly sealed against rain and very hard to reassemble to get a good O-ring seal after battery replacement

- Transmitter power is totally inadequate and so is its internal antenna

- Its fault reportng and fault recovery algortithms are not as decsribed in the manual, nor are they effective. Ther peroid before 'no signal' kicks in is MUCH less than the 24 hours they say, and the condition can only be cleared by a reboot. I..e one missed signal and the thing stops working permanently until power cycled.

It is however *just about* usable. compared with going out in the cold climbing a ladder unscrewing te filler cap and sticking a rod in the tank.

On my list of jobs is to re-pair the transmitter and receiver to try to get them to go. And this is with a tank inside its own private room.

The old tank had a sight glass. Pull a tap on the side, and look at the level in a plastic tube. Accurate to the mm, which I gradually worked out was about a litre.

I wish I still had it.

Andy

Dont even try.

I think next time I will buid somethng with a raspberry Pi..

IME one year on and the 'glass' is yellow and totally opaque.

Just thinking: if you built a tank bubbler, and used a U-tube manometer with the oil in the tank as the working fluid, wouldn't the height difference in the U-bend be the level of oil in the tank?

Like the second drawing in the link above, only with a rubber squeezyball or such as an air supply... No extra holes in the tank, no leak if the contraption fails.

Thomas Prufer

It seems like it relies on a regulated flow of gas, if you tried to "pump" it from a small rubber ball (e.g. similar to a sphygmomanometer, which is what I think you're suggesting) wouldn't you just set off an oscillation in the 'U' tube than get a steady reading?

Yes, possibly.(Though I was thinking of a rubber-ball-pump that inflates a balloon-like thing inna net, and a small orifice lets through a steady stream of air... my google-fu is insufficient to find a picture). But using a non-return-valve and pumping until the maximum is reached would work, I think.

There's such thing, ready-made, Treznal, with an atrocious translation:

Little pump thing an the right, pump it, and it reads 0%-100% (though I haven't found if it's adjustable to read 100% for different tank depths...), and it has a hose dropped to the bottom of the tank, nothing else.

Thomas Prufer