Recommended digital meters.

[Yggdrasil]

Hi All!
I have come to a point where I need to acquire a PH meter at the least.
Is it advisable to get a combo between pH and ORP meter?
Any recommendations on brand/type?
Will a quality meter with replaceable electrodes be a "must"?

BR Per-Ove

 

[4metals]

What are you you planning to use the pH meter for? If it is solely for waste treatment or occasionally measuring a solution you are refining for pH you may be better off just using a good pH paper. I have found these PeHanon papers to be excellent.

http://www.mn-net.com/tabid/10470/Default.aspx

They are available in broad range or narrow range. I always have a package of 1-12 range in my pocket when I am in a refinery.

If you are measuring pH multiple times daily then calibration of the probe is a small price to pay for convenience, but if you only need it occasionally, papers are a good alternative. The same company also has semi quantitative strips for Cyanide and heavy metals.

 

[Yggdrasil]

Thanks 4Metals!
That is probably what I'll do just now.
Actually I thought I already had ordered it , but it slipped during my last order.

I expect to have a need for ORP readings in the future, but I'll address that when the time arrives.

With reference to the initial question, are there any recommendations with respect to brand/type?
Or will any half decent apparatus do the job well enough?

BR PoA

 

[goldsilverpro]

I totally agree with 4metals. In plating, I used a ph meter often but, for refining, I can't remember ever using one. So much easier and much, much faster to use pH papers, like 4metals suggested. This isn't rocket science and, to me, pH meters are a total pain. In the right hands, they are more accurate than papers. In the hands of someone that doesn't know exactly what they're doing, they can be quite inaccurate. Don't waste your money on a meter, something you don't need - use papers.

 

[upcyclist]

I bought my pH meter for working with cyanide (which I mostly don't do anymore). I do use the meter when I'm trying to figure out if I've raised the pH of my final waste stage high enough--especially with dirty solutions, I'm not that good with judging pH from paper (e.g., how much "slightly bluish" is pH 8?). So I use paper until I'm in the neighborhood, then the meter to see when I'm there. As I do it more, I'll probably not use the meter as much.

 

[4metals]

The papers I recommended in this thread actually have the scale on each strip of test paper so the indicating section is wet by the same chemistry as the scale. Pretty easy to get either a gross reading of 1 thru 12 on the broad range and then they have papers which only cover a 2 pH unit range. You can hit your target pretty good with papers.

This ain't granpa's litmus paper!

 

[kadriver]

The papers I recommended in this thread actually have the scale on each strip of test paper so the indicating section is wet by the same chemistry as the scale. Pretty easy to get either a gross reading of 1 thru 12 on the broad range and then they have papers which only cover a 2 pH unit range. You can hit your target pretty good with papers.

This ain't granpa's litmus paper!

I'm going to get some of those papers. But will they be able to get my solution to "exactly 7.5" when doing a bromate hydrolysis? Or would a good meter be needed for that?

kadriver

 

[kurtak]

I'm going to get some of those papers. But will they be able to get my solution to "exactly 7.5" when doing a bromate hydrolysis? Or would a good meter be needed for that?

kadriver

If you get "both" wide range & narrow range papers you should not have a problem hitting your target

your wide range will get you in the ball park - say somewhere in the 7 - 8 range (plus/minus "a bit")

your narrow range will then get you to your decimal target

Edit to add; - the narrow range paper is quite accurate - unless you are color blind

Kurt