Jaycar pH meter

[Clifford Heath]

Anyone know whether this item's any good? Not so much
how accurate is it, but can it be expected to last a
while? Anything else I should know? I'm unfortunate
enough to have a pool to maintain, and anything that
makes it easier would be welcome. I realise this is
aus.electronics, not aus.pool.chemistry, but I figure
folk here shop at Jaycar and are often a cluey bunch,
so... any thoughts?

 

[Rob*]

"Clifford Heath" <no@spam.please.net> wrote in message
news:4471b6ec$0$7900$afc38c87@news.optusnet.com.au...

Anyone know whether this item's any good? Not so much
how accurate is it, but can it be expected to last a
while? Anything else I should know? I'm unfortunate
enough to have a pool to maintain, and anything that
makes it easier would be welcome. I realise this is
aus.electronics, not aus.pool.chemistry, but I figure
folk here shop at Jaycar and are often a cluey bunch,
so... any thoughts?

I think pH sensors may have a finite lifetime. I don't know anything about
the Jaycar unit but I reckon you might be better off sticking with the
little (pH/Alkalinity/Cyanuric Acid/Chlorine) dip test strips - $12 for 50
strips isn't too bad and might be a hell of a lot simpler than stuffing
about with a pH meter.

 

[Clifford Heath]

Rob* wrote:

I think pH sensors may have a finite lifetime.

Yeah, well, so does the sun. Any idea how long?

I don't know anything

Apparently not. The little strips are very inaccurate,
show multiple different colours on the one tab - none of
them a very close match to the colours on the container -
and they can be adversely affected by different water
conditions unrelated to pH. There's much less "stuffing
about" just poking a probe in the water, especially if
you can get repeatable results with one.

Thanks anyway, I'll try sci.chem.analytical.

 

[The Real Andy]

On Mon, 22 May 2006 23:04:44 +1000, Clifford Heath
<no@spam.please.net> wrote:

Anyone know whether this item's any good? Not so much
how accurate is it, but can it be expected to last a
while? Anything else I should know? I'm unfortunate
enough to have a pool to maintain, and anything that
makes it easier would be welcome. I realise this is
aus.electronics, not aus.pool.chemistry, but I figure
folk here shop at Jaycar and are often a cluey bunch,
so... any thoughts?

The lifetime of the device depends on how long the reference liquid
lasts inside the sensor. A good quality sensor will last you years, if
treated with care. I am not sure how much the jaycar unit is worth,
but its probably not going to be a lab grade sensor. However, you may
find it fits your needs quite well. Buffer sollutions can be had from
industrial chemists for testing, and you may even find them at your
local aquarium supplier. I guess you could also take a water sample to
your pool shop once a year for comparison purposes.

ITs been a long time since I was in this industry, but IIRC the senors
I used to buy were shipped with a little snap on cap filled with
distilled water to extend the life. If the jaycar beast comes with
such a fitting then keep it fitted, and filled.

 

[The Real Andy]

On Wed, 24 May 2006 21:43:12 +1000, The Real Andy
<will_get_back_to_you_on_This@b.c> wrote:

On Mon, 22 May 2006 23:04:44 +1000, Clifford Heath
no@spam.please.net> wrote:

Anyone know whether this item's any good? Not so much
how accurate is it, but can it be expected to last a
while? Anything else I should know? I'm unfortunate
enough to have a pool to maintain, and anything that
makes it easier would be welcome. I realise this is
aus.electronics, not aus.pool.chemistry, but I figure
folk here shop at Jaycar and are often a cluey bunch,
so... any thoughts?

The lifetime of the device depends on how long the reference liquid

Actually, the more i think about this, IIRC The reference liquid is
just a ph neutral liquid. I think lifetime also depends on the how
long the liquid in the measurment electrode lasts too, which again
IIRC is just a ph neutral liquid. I went looking for my old
instumentation books but I cant seem to find them anywhere.

lasts inside the sensor. A good quality sensor will last you years, if
treated with care. I am not sure how much the jaycar unit is worth,
but its probably not going to be a lab grade sensor. However, you may
find it fits your needs quite well. Buffer sollutions can be had from
industrial chemists for testing, and you may even find them at your
local aquarium supplier. I guess you could also take a water sample to
your pool shop once a year for comparison purposes.

ITs been a long time since I was in this industry, but IIRC the senors
I used to buy were shipped with a little snap on cap filled with
distilled water to extend the life. If the jaycar beast comes with
such a fitting then keep it fitted, and filled.

 

[John_H]

Clifford Heath wrote:

Anyone know whether this item's any good? Not so much
how accurate is it, but can it be expected to last a
while?

I have no idea what principle the Jaycar meter operates on, but even
the laboratory grade instruments are high maintenance and prone to
failure. The glass membrane which forms the half cell is prone to
both contamination and breakage.

What have got against good quality indicator papers?

--
John H

 

[Clifford Heath]

The Real Andy wrote:

I think lifetime also depends on the how
long the liquid in the measurment electrode lasts too

Thanks Andy, I got a similar response in sci.chem.analytical.
Concensus is the cheap meters are erratic when new, and not
likely to improve with age .