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pH testing, paper strips or an electronic device
- Thread starter mombreast
- Start date
mombreast
Rising Star
Thanks for you input.
It seems to me that most cheeper pH meters are for testing water in the sea,
river, rain, or fish tank.
Electrodes are inside the cap and have to be immersed in the liquid 1 inches or so.
It must to be difficult to use it for small vials.
So I was wondering if expensive ones could be used in chemical experiments.
Maybe not?
It seems to me that most cheeper pH meters are for testing water in the sea,
river, rain, or fish tank.
Electrodes are inside the cap and have to be immersed in the liquid 1 inches or so.
It must to be difficult to use it for small vials.
So I was wondering if expensive ones could be used in chemical experiments.
Maybe not?
panoramix
Rising Star
Not Found | - ScientificsOnline.com
even sheaper than i first postet
69ron
Rising Star
I have many different kinds of pH paper, and have gone through countless digital pH meters.
I've had the cheapest pH meters, the most expensive ones, and several in between. They are all very crappy. There is no such thing as a good pH meter. They all go bad pretty quickly and are plagued with problems. They need to be cleaned often, kept in storage solution when not in use, treated like a delicate flower, and they must be calibrated all the time. They are a pain in the ass.
If buying a pH meter, get the cheapest one you can get that has the accuracy you need. The more pricey ones are just as crappy, but can read more accurately while they are working. But they go bad just as fast as the cheapest ones you can get.
My advice is, if you don't need super accurate pH readings, get a very cheap pH meter. Like all pH meters, it's going to go bad. Don't waste money on a very pricey pH meter thinking it's not going to go bad. They all go bad. And it usually goes bad right when you need it working the most.
No matter what, you're going to want to have pH paper. They are much more convenient. For those times that you don't care if the pH is 3 or 4, pH papers are more handy. You can just grab them and use them. No cleaning, no calibration, no hassles. And best of all, pH papers are not electronic so they don't go bonkers on you right in the middle of testing, which every single digital pH meter does eventually.
For those times when you need to know if the pH is 8 or 8.5, you'll need a meter. There are pH papers that are supposed to read the difference between 0.5 increments, but they don't really do the job well. I've found many papers will read pH 8.5 as 9 or 8, or 8.5. It's often very hard to judge such an increment with pH paper. I have several kinds of paper with different resolutions and they all have this problem. They are not accurate, but they always work.
There are times when you absolutely can't use pH paper. One such case is when the fluid is too richly colored that it colors the paper making it impossible to judge the color of the paper.
So, bottom line, you're likely going to need both a meter and paper.
[edit: wow...so many typos I had to fix! Sorry about that]
I've had the cheapest pH meters, the most expensive ones, and several in between. They are all very crappy. There is no such thing as a good pH meter. They all go bad pretty quickly and are plagued with problems. They need to be cleaned often, kept in storage solution when not in use, treated like a delicate flower, and they must be calibrated all the time. They are a pain in the ass.
If buying a pH meter, get the cheapest one you can get that has the accuracy you need. The more pricey ones are just as crappy, but can read more accurately while they are working. But they go bad just as fast as the cheapest ones you can get.
My advice is, if you don't need super accurate pH readings, get a very cheap pH meter. Like all pH meters, it's going to go bad. Don't waste money on a very pricey pH meter thinking it's not going to go bad. They all go bad. And it usually goes bad right when you need it working the most.
No matter what, you're going to want to have pH paper. They are much more convenient. For those times that you don't care if the pH is 3 or 4, pH papers are more handy. You can just grab them and use them. No cleaning, no calibration, no hassles. And best of all, pH papers are not electronic so they don't go bonkers on you right in the middle of testing, which every single digital pH meter does eventually.
For those times when you need to know if the pH is 8 or 8.5, you'll need a meter. There are pH papers that are supposed to read the difference between 0.5 increments, but they don't really do the job well. I've found many papers will read pH 8.5 as 9 or 8, or 8.5. It's often very hard to judge such an increment with pH paper. I have several kinds of paper with different resolutions and they all have this problem. They are not accurate, but they always work.
There are times when you absolutely can't use pH paper. One such case is when the fluid is too richly colored that it colors the paper making it impossible to judge the color of the paper.
So, bottom line, you're likely going to need both a meter and paper.
[edit: wow...so many typos I had to fix! Sorry about that]
the issue isn't the pH meter with the more expensive ones, it's the calomen electrodes that need special treatment
i.e. storage in AgCl sol'n
but those types are very accurate. thermo orion meters are industry standard
I have a 230A, got it on e.bay.
the electrode was busted, luckily my tech friend from the school gave me one
i.e. storage in AgCl sol'n
but those types are very accurate. thermo orion meters are industry standard
I have a 230A, got it on e.bay.
the electrode was busted, luckily my tech friend from the school gave me one
definitely
for all practical purposes, the Hanna pH Checker would suit the casual hobbyist. it's typically $30 or less
for all practical purposes, the Hanna pH Checker would suit the casual hobbyist. it's typically $30 or less