Inexpensive ph meter

On Sat, 28 Feb 2004 18:36:48 -0500, "Francis A. Miniter"
wrote:

The probe is part of it. It is all very compact and can be put in your
pocket. The probe end of it screws off so it can be replaced if it fails.

Or gets ionized to the point that it is not producing good
readings. I once measured a 5% solution of sodium hydroxide and
immediately fried the meter. I thought that soaking it in glacial
acetic acid word undo the damage but alas it was destroyed.


Regards,

John S. Douglas, Photographer - http://www.darkroompro.com
Please remove the "_" when replying via email

The simplest is to use pH paper calibrated in 1/2 units.


On 28 Feb 2004 14:09:10 -0800, (Dan Quinn) wrote:

"Lew" wrote

Ouch!

Don't panic just yet. I've been using a Hanna pHep meter with
good repeatability. Actually I'm shopping for a meter with remote
probe. There are some on eBay for under $70 IIRC.
I think Mr. R. Suzuki is not telling us the whole story. He may be
talking only of units which have a resolution of .01 of even .001.
I think .1 accurate enough although .01 would be OK.
I can't say for sure, but I think he may be overboard on this one.
Smack dab on home base is closer than I need be. Dan

The simplest is to use pH paper calibrated in 1/2 units.


I've been following this thread and wondered why nobody. seems to use litmus
paper.
_________________
Ready, Fire, AIM.
Bruce
Brooklyn, N.Y.

"Gary Banuk" wrote

The simplest is to use pH paper calibrated in 1/2 units.

Available at pool supply outlets, and at aquarium
stores for 10x the price and at drugstores at 100x
the price.

And while at the pool store, along with ordering a pool
for the summer ahead, be sure to pick up some Sodium
Sulfite, Sodium Thiosulfate* and Sodium Carbonate.

* Language note: standard American English is "sulfur" but standard
British English is "sulphur," and New Zealand English follows the
British model in this case. Similarly, standard American English is
"sulfate" but standard British (and New Zealand) English is "sulphate".

From

http://zenvirus.com/poems/sodium-thiosulphate.html

Which I found when googling for "sulfate sulphate" and
where you will find, well, you will have to find out
for yourself...

Google first, question later.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

"Bruce" wrote

I've been following this thread and wondered why nobody. seems to use litmus
paper.

Cough: google: "litmus paper"

Some ignorami (health food stores & co.) confuse litmus paper (red or
blue strips in a corked glass vial) with pH paper, available in .5 or
..1 gradations, and which comes on a spool in a nifty plastic case w/ a color-
match chart.

Litmus paper is paper soaked in red cabbage juice. It's good for telling
baking soda from vinegar, but not much else. You may as well buy a head
of red cabbage (cheaper) and after checking the pH you can make a dandy salad:
Red cabbage, endive and diced fresh pears with blue cheese crumbled over the top,
a French or a tomato & celery vinaigrette dressing works well.

Litmus paper is not a very (not allot) accurate indication of pH. Works great
in a Gilmour Chemistry Set ("Tell Mom: 41 great chemicals, including magnesium,
glycerin, pot. permanganate, powdered aluminium, powdered iron ...") but not
good for much else.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

I have tried the pool supply route, but no one seems to stock thiosulfate
anymore. Don't know why.
-Lew

"Bruce" wrote

I've been following this thread and wondered why nobody. seems to use
litmus
paper.

Cough: google: "litmus paper"

Some ignorami (health food stores & co.) confuse litmus paper (red or
blue strips in a corked glass vial) with pH paper, available in .5 or
.1 gradations, and which comes on a spool in a nifty plastic case w/ a color-
match chart.

Litmus paper is paper soaked in red cabbage juice. It's good for telling
baking soda from vinegar, but not much else. You may as well buy a head
of red cabbage (cheaper) and after checking the pH you can make a dandy
salad:
Red cabbage, endive and diced fresh pears with blue cheese crumbled over the
top,
a French or a tomato & celery vinaigrette dressing works well.

Litmus paper is not a very (not allot) accurate indication of pH. Works
great
in a Gilmour Chemistry Set ("Tell Mom: 41 great chemicals, including
magnesium,
glycerin, pot. permanganate, powdered aluminium, powdered iron ...") but not
good for much else.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.


Okay.
_________________
Ready, Fire, AIM.
Bruce
Brooklyn, N.Y.

I have an almost full box of short range, 0.5 pH paper, made in Germany.
I've tried it before going the cheap pH meter route.

Jorge

Gary Banuk wrote in
:

The simplest is to use pH paper calibrated in 1/2 units.

"Lew" wrote
I have tried the pool supply route, but no one seems to stock thiosulfate
anymore. Don't know why.


http://www.midwestpoolsupply.com/che...sanitizers.htm

50 lbs: $48 + shipping. Look out for shipping $, some chemical
houses will charge more for shipping 50lb of the stuff than
for the stuff itself.

Don't be afraid to 'special order' it from your friendly
(and rapacious) pool supplier.

TTTT: I use Freestyle's Arista brand Ammonium Thiosulfate
rapid fix at $14/gal. Mix 1:9 for paper, about $1.40/gal.
OTOH it is 1:4 for film, about $2.80/gal. This is still
the best deal going, IMHO.

S. Thio. fix is 250g s. thio./liter or about 2 lb/gal, yielding
$2/gal. But then you need to add sulfite, metaborate/acetic
acid (depending on religion) .... Additionally, Anchell/Troop
indicate Kodak sez (or sed, till they closed the research dept.)
S. Thio is no good for modern emulsions (film - too much iodide?)
(and though they sell S. Thio. Fix by the tonne) and that A.
Thio should be used instead.

FWIW Kodak S. Thio fixer powder is $22 for 5 gal worth:
$4.40/gallon. And Kodak Rapid Fix is $10/gal.

Care to support our Great Yellow Father in his dotage? Only
cost 6x more -- Oh, well, I thought not. Gee, and Kodak
spends $10 million/year on management consultants BCG, McKinsey
& Booz-Allen. Having done a 5-year stint at Booz, can't say
I'm surprised.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

"Nicholas O. Lindan" wrote

S. Thio. fix is 250g s. thio./liter or about 2 lb/gal, yielding
$2/gal. But then you need to add sulfite, metaborate/acetic
acid (depending on religion) .... Additionally, Anchell/Troop
indicate Kodak sez (or sed, till they closed the research dept.)
S. Thio is no good for modern emulsions (film - too much iodide?)
(and though they sell S. Thio. Fix by the tonne) and that A.
Thio should be used instead.

S. Thio can be used very dilute and needs no additives.
The ammonium ion's silver complexing capacity in the presence
of iodide is nil. It is the thiosulfate ion which holds the silver.
Cyanide will also complex with silver in the presence of iodide. Dan