Sensor Systems Watchman battery pack

[Jezzer]

Hi

I have a 1100 litre oil tank fitted with a Sensor Systems Watchman
wireless transmitter, and a receiver with a 7-segment display in the
house, which displays an oil level indication between 0-9,F (0=empty,
F=Full)

The transmitter is powered by a 'battery power tube' which retails for
£26.50 from Sensor System's website (see http://www.sensor-systems.com/shop.html)
I've bought a replacement in the past but this time around it occurred
to me that it just looks like a copper tube that contains regular AAA
batteries. So yesterday I removed it, knocked the cap off and sure
enough, 4 x AAA Duracells inside a plastic insert.

I replaced them with 4 new Duracell AAA batteries and refitted the
pack and it worked, but today the battery low indicator is flashing on
the receiver/display unit already. I am concerned that I may have
refitted the battery pack the wrong way around, ie. reversed polarity.
Not sure if the transmitter would have worked in this case but can't
think why else the batteries would have run out so fast.

Anyone have any ideas, or know what the polarity of the batteries
should be?

Thanks in anticipation!
Jez

[Dave Liquorice]

On Mon, 7 Dec 2009 09:48:13 -0800 (PST), Jezzer wrote:

> The transmitter is powered by a 'battery power tube' which retails for
> £26.50

Plus Postage plus VAT and I can't find what their postage charges are
easily so I'd guess about £35 delivered. Yipes!

> So yesterday I removed it, knocked the cap off and sure enough, 4 x AAA
> Duracells inside a plastic insert.
>
> I replaced them with 4 new Duracell AAA batteries and refitted the
> pack and it worked, but today the battery low indicator is flashing on
> the receiver/display unit already.

Make sure all the connections are clean including the ends of the
batteries. I've known them to be coated with a thin insulating layer
that is enough to stop kit working, quick rub on your trousers cleans
it off. BTDTGTTS.

> Anyone have any ideas, or know what the polarity of the batteries
> should be?

The same as the ones you took out. B-)

Moral: When dismantling kit for which you have no instructions make
notes and/or take photos through the dismantling process of how it
was orginally assembled.

I doubt the Tx would have worked at all with incorrect polarity, so
I'd check for good clean connections and no ingress of wet. Did put
the new batteries into the sleeve? Do they slide easily inside that
sleeve? As the batteries contract as they cool outside it might
weaken the contact presure between them. BTDTGTTSAW.

--
Cheers
Dave.

[Harry Bloomfield]

Someone in (I think) this newsgroup, came up with an interesting method
for draining radiators within the past couple of days. It involved
fixing a Scrader valve to a drilled bleed screw, so that air pressure
could be blown into the radiator, to blow the water back down through
the rad tails and up to the header tank.

Clever I thought, but what the idea still needs is some (similarly
clever) means by which to work out that the level has gone down far
enough to clear the bottom of the radiator and or the valves, other
than cracking a connection open to see, or blowing enough air in that
the entire system has to be bled afterwards.

Anyone suggest a way to do it?

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

[Bob Minchin]

Drive out the water with the system on and the radiator hot and feel the
temperature drop as you pump. Even more fun if you have access to a
thermal imaging camera!
Bob

[Dave Liquorice]

On Tue, 08 Dec 2009 18:28:55 +0000, Bob Minchin wrote:

> Drive out the water with the system on and the radiator hot and feel the
> temperature drop as you pump.

Or try one of those liquid crystal thermometer strips. You wouldn't
want the rad at operating temperature (60C+) just warm.

> Even more fun if you have access to a thermal imaging camera!

Probably outside most of our budgets.

--
Cheers
Dave.