Sciencemadness Discussion Board

PH Meter

RonPaul2012 - 25-7-2012 at 12:39

I am in the market for a Ph meter.

I would like to have one I could use for titrations.

Does anybody have any suggestions ?

zoombafu - 25-7-2012 at 13:46

They aren't really worth the price unless you are regularly checking pH, or if what you are doing needs a very precise pH. I have one that I got for free, otherwise I wouldn't have gotten one.

xobon - 25-7-2012 at 15:11

You can get one on ebay for less than $30. I use this one with the long replaceable probe ($29.90). It's great, everyone should have one. No more ph paper, lol.

http://www.ebay.com/itm/Digital-Pen-type-pH-Meter-Tester-wit...

RonPaul2012 - 26-7-2012 at 11:31

I would really like one with a portable probe (is that the right word ?).

I am sick of using indicators and PH paper.

I would like to do precise calculations , not just guestimations like "It's red. I guess that means it's a PH of 1 or something"

Sooooooooooo unscientific :D

[Edited on 26-7-2012 by RonPaul2012]

RonPaul2012 - 27-7-2012 at 16:51

This is a picture of the setup I would like to have.



titration.jpg - 12kB

Swede - 28-7-2012 at 05:09

I have and use a Milwaukee Instruments pH meter, and like it. You don't want to get one of the super-cheap pH "pens". Get a mid-grade instrument if you can afford it. And get a decent probe.

pH probes are one of the few things I'll not buy on eBay. Probes eventually drift badly, the response time slows, and in the end, if it's a sealed unit as most of the less-expensive probes are, it becomes scrap. Some guy digs them out of a dumpster at a major lab, and voila! they are sold on eBay.

You'll need standardized buffers, and instructions for calibration on the unit. Calibration needs to be frequent. A probe can drift just sitting on a shelf for a few weeks.

RonPaul2012 - 28-7-2012 at 11:12

Good to know.

Thanks for the help Swede.

Mildronate - 28-7-2012 at 13:09

Quote: Originally posted by RonPaul2012  
This is a picture of the setup I would like to have.



When you are spekaing about mesasuring aparatus its not about picture its about parameters like acuarity, slectivity.. pH meter is milivoltmeter you also need pH probes, forget abaout garden pH meters, I use soviet pHmeter PH-121, also i had one portable soviet pHmeter and one ionometer ad soviet setup for autotitration, but i never use this setup at home.