pH meters
 

I bought a pH meter which is aimed at gardeners ...
http://www.amazon.co.uk/Gardman-Soil...7222580&sr=8-3

I thought I could also use it on liquids ... but I have serious doubt it
is reading acidity correctly.
Is there a simple way of testing ?

In water it read 7 .. (so OK there) ... I tried in in a bottle of white
vinegar with is rated at 5% acidity it reads pH 6

Is there a simple home way of testing calibration ?

pH meters
 

On Sun, 09 Sep 2012 21:32:26 +0100, Rick Hughes
wrote:

Is there a simple home way of testing calibration ?

google diy buffer solutions.

pH meters
 

On 09/09/2012 21:32, Rick Hughes wrote:
I bought a pH meter which is aimed at gardeners ...
http://www.amazon.co.uk/Gardman-Soil...7222580&sr=8-3


I thought I could also use it on liquids ... but I have serious doubt it
is reading acidity correctly.
Is there a simple way of testing ?

In water it read 7 ..

You are very lucky to get that result it was pure chance. Rainwater
usually has enough CO2 dissolved to be slightly acidic pH 5 and tapwater
is buffered towards alkaline to avoid dissolving the pipes.

(so OK there) ... I tried in in a bottle of white
vinegar with is rated at 5% acidity it reads pH 6

Vinegar is a fairly dilute solution of a weak acid but it should be
about pH 3 or so. You can buy indicator solution or strips of paper for
next to nothing that cover the 0-14 range (or selected ranges). eg

http://www.ebay.co.uk/sch/i.html?_nkw=ph+test+paper

Is there a simple home way of testing calibration ?

Of the things you can likely find on the kitchen/garage shelf. Sodium
bicarbonate, carbonate, ammonia and sodium hydroxide (careful) as bases
in rough order and acetic acid, citric acid (lemon juice), sulphuric,
hydrochloric acid as a strong acids.

Take care with any strong alkali or acid they can be unforgiving.

--
Regards,
Martin Brown

pH meters
 

vinegar with is rated at 5% acidity it reads pH 6


On 09/09/2012 21:47, Martin Brown wrote: On 09/09/2012 21:32, Rick
Hughes wrote:
I bought a pH meter which is aimed at gardeners ...


Of the things you can likely find on the kitchen/garage shelf. Sodium
bicarbonate, carbonate, ammonia and sodium hydroxide (careful) as bases
in rough order and acetic acid, citric acid (lemon juice), sulphuric,
hydrochloric acid as a strong acids.

Take care with any strong alkali or acid they can be unforgiving.



But how would I know what pH reading I should get from them ?
i.e is lemon juice pH 1,2,3,4 ?

pH meters
 

On 09/09/2012 22:12, Rick Hughes wrote:
vinegar with is rated at 5% acidity it reads pH 6


On 09/09/2012 21:47, Martin Brown wrote: On 09/09/2012 21:32, Rick
Hughes wrote:
I bought a pH meter which is aimed at gardeners ...


Of the things you can likely find on the kitchen/garage shelf. Sodium
bicarbonate, carbonate, ammonia and sodium hydroxide (careful) as bases
in rough order and acetic acid, citric acid (lemon juice), sulphuric,
hydrochloric acid as a strong acids.

Take care with any strong alkali or acid they can be unforgiving.



But how would I know what pH reading I should get from them ?
i.e is lemon juice pH 1,2,3,4 ?

Use the cheap paper test strips from eBay instead.

Are you incapable of using Google or something?

http://en.wikipedia.org/wiki/Ph_scale


--
Regards,
Martin Brown

pH meters
 

In message , Rick Hughes
writes
I bought a pH meter which is aimed at gardeners ...
http://www.amazon.co.uk/Gardman-Soil...001P3XAEE/ref=
sr_1_3?ie=UTF8&qid=1347222580&sr=8-3

I thought I could also use it on liquids ... but I have serious doubt
it is reading acidity correctly.
Is there a simple way of testing ?

In water it read 7 .. (so OK there) ... I tried in in a bottle of white
vinegar with is rated at 5% acidity it reads pH 6

Is there a simple home way of testing calibration ?

You can get buffer solutions of (IIRC) pH 4.7 and 11 which are the
standards used for calibration


--
geoff

pH meters
 

Rick Hughes wrote:

I bought a pH meter which is aimed at gardeners ...
http://www.amazon.co.uk/Gardman-Soil...1P3XAEE/ref=sr
_1_3?ie=UTF8&qid=1347222580&sr=8-3

I thought I could also use it on liquids ... but I have serious doubt it
is reading acidity correctly.
Is there a simple way of testing ?

I think it's RTFM time. I had one of those some years ago. They are not
very good. As I recall the instructions state that they will not work
with solutions they will only work when rammed into the soil. They are
not proper pH meters which have a porous glass electrode, they work on
the voltage generated by the bimetallic tip when in contact with soil
and apparently that will not work properly in a liquid.

At the time I had access to a lab with a proper pH meter and the Gardman
types produced very odd results when used with pH reference buffer
solutions.

Short summary, the Gardman and similar "pH meters" are about as much use
as if they had been made from chocolate.

pH meters
 

On 10/09/2012 23:33, Steve Firth wrote:

I think it's RTFM time. I had one of those some years ago. They are not
very good. As I recall the instructions state that they will not work
with solutions they will only work when rammed into the soil. ..


Short summary, the Gardman and similar "pH meters" are about as much use
as if they had been made from chocolate.


The instructions on mine didn't say anything about 'no liquids" about
all it says ...
... "clear away top soil, add water, mix with soil, insert probe, wait 1
minute take reading."


You may be right that it will not be much good.

I wonder if I can get a pH probe to use with a MultiMeter ?

pH meters
 

On 10/09/2012 20:44, geoff wrote:
In message , Rick Hughes
writes
I bought a pH meter which is aimed at gardeners ...
http://www.amazon.co.uk/Gardman-Soil...001P3XAEE/ref=
sr_1_3?ie=UTF8&qid=1347222580&sr=8-3

I thought I could also use it on liquids ... but I have serious doubt
it is reading acidity correctly.
Is there a simple way of testing ?

In water it read 7 .. (so OK there) ... I tried in in a bottle of
white vinegar with is rated at 5% acidity it reads pH 6

Is there a simple home way of testing calibration ?

You can get buffer solutions of (IIRC) pH 4.7 and 11 which are the
standards used for calibration




Thnx .... found some on ebay

pH meters
 

On 10/09/2012 10:30, Chris Hogg wrote:
On Sun, 09 Sep 2012 21:32:26 +0100, Rick Hughes
wrote:



http://www.engineeringtoolbox.com/food-ph-d_403.html

http://chemistry.about.com/od/acidsbases/a/phtable.htm



Exactly what I was after .... Thank you

pH meters
 

On 09/09/2012 22:25, Tim Streater wrote:
In article ,


**** me. Orange juice is 3 lemon juice is 2 according to a simple check
in Wikipedia. And you mean e.g. not i.e.


Sorry that I have upset you so much .... please feel free to ignore any
future emails from me.

pH meters
 

On 11/09/2012 22:47, Tim Streater wrote:
In article ,
Rick Hughes wrote:

On 09/09/2012 22:25, Tim Streater wrote:
In article ,

**** me. Orange juice is 3 lemon juice is 2 according to a simple check
in Wikipedia. And you mean e.g. not i.e.

Sorry that I have upset you so much .... please feel free to ignore
any future emails from me.

You haven't *upset* me dear boy, just astonished me that you were unable
to discover that for yourself on WinkyPedia or elsewhere. Took me all of
4.27 secs. Hmmm, must be modern education systems.


It took you that long because you knew what to search for. If you know
nothing about something, you sometimes don't know where to start.

pH meters
 

On 12/09/2012 09:07, stuart noble wrote:
On 11/09/2012 22:47, Tim Streater wrote:
In article ,
Rick Hughes wrote:

On 09/09/2012 22:25, Tim Streater wrote:
In article ,

**** me. Orange juice is 3 lemon juice is 2 according to a simple
check
in Wikipedia. And you mean e.g. not i.e.

Sorry that I have upset you so much .... please feel free to ignore
any future emails from me.

You haven't *upset* me dear boy, just astonished me that you were unable
to discover that for yourself on WinkyPedia or elsewhere. Took me all of
4.27 secs. Hmmm, must be modern education systems.


It took you that long because you knew what to search for. If you know
nothing about something, you sometimes don't know where to start.

When asking about "pH" that seems like a reasonable search term.

Wiki comes about 4th or 5th after "buy pH sponsored adverts" on Bling.

I particularly liked the first ad hit YMMV

Ads

Ph Urine at Amazon.co.uk
www.amazon.co.uk/Ph Urine
Low Prices on Ph Urine. Free UK Delivery on Amazon Orders

Reminds me of a problem we once had importing some elephant urine for
pregnancy tests (got impounded at customs). Delay was so great that the
elephants were obviously pregnant so no-one bothered to follow up. Eight
months later we were notified that if we did not go and pay up to
collect our goods it would be auctioned off the the highest bidder!

He would have been much better off with paper test strips off eBay.
(or a bottle of pH indicator solution)
The "soil" pH meter is junk and cannot be relied upon.

--
Regards,
Martin Brown

pH meters
 

Martin Brown wrote:

Reminds me of a problem we once had importing some elephant urine for
pregnancy tests (got impounded at customs). Delay was so great that the
elephants were obviously pregnant so no-one bothered to follow up. Eight
months later we were notified that if we did not go and pay up to collect
our goods it would be auctioned off the the highest bidder!

When I was at Uni the senior lecturer was researching neural cell lipid
changes in humans on poor diets. We got a call from the airport saying he
had to go to cargo and talk to the Revenue. They had a case of steel cans
consigned to him and were insisting that he open them for inspection. He
suggested that they really didn't want to do that because... then some
officious prat told him that no one tells the revenue what to do. They got
a can opener and opened a can ... of human brains. Apparently the revenue
man projectile vomited.

pH meters
 

On 2012-09-12, Steve Firth wrote:

Martin Brown wrote:

Reminds me of a problem we once had importing some elephant urine for
pregnancy tests (got impounded at customs). Delay was so great that the
elephants were obviously pregnant so no-one bothered to follow up. Eight
months later we were notified that if we did not go and pay up to collect
our goods it would be auctioned off the the highest bidder!

I hope you wrote back, "Are you taking the ****?"


When I was at Uni the senior lecturer was researching neural cell lipid
changes in humans on poor diets. We got a call from the airport saying he
had to go to cargo and talk to the Revenue. They had a case of steel cans
consigned to him and were insisting that he open them for inspection. He
suggested that they really didn't want to do that because... then some
officious prat told him that no one tells the revenue what to do. They got
a can opener and opened a can ... of human brains. Apparently the revenue
man projectile vomited.

And uk.d-i-y wants to know --- what kind of can opener?