Old Reviews Question regarding shelf life of PH Calibration Fluid

[BLACKBRIAR]

Happy New Year to all of you, and nice to meet you. Thank you for stopping by.

I recently acquired an HM Digital PH-200 and the HM DCOM100 meter for measuring TDS/EC and temp. They were bought locally from an older gentleman and he gave with it Advanced Nutrients PH UP and DOWN. These bottles are both almost completely full. I have poked around and the general consensus seems to be that they have an indefinite shelf life. I could be wrong here...

Also Given to me with them were bottles of Calibration fluid (7.0 and 4.01 I believe) General Hydroponics

And lastly an electrode storage solution/calibration fluid with a value of 1500ppm,also General Hydroponics.

My findings have been the calibration fluids can expire quickly, sometimes 6 months or less.

Question is this. How long are the calibration and PH UP/DOWN usually okay for? Just would like some clarification on that.

I put new batteries in the HM PH-200 and went to calibrate it. It would not get anywhere close to 7.0 in the solution I had. It was coming in at 8.5 give or take a little. Cheapest route is to first try new solution $9 (on the way) and if not that- could be the electrode itself? If anyone would like to weigh in on what they know, feel free.

Hope that all was clear, Like I said thank you for checking this out. Blackbriar

 

[namvet25]

Did you try the 4.0 solution? If that doesn't work,it must be your meter.My solution is a year old and still works good.:smokebuds:

 

[BLACKBRIAR]

Namvet, Happy New Year! I am assuming you were in the service. Thank you for sacrificing in order to keep us safe here.

I did not try the 4.01. When calibrating to 7.0, the closest I could get was 8.3-8.5. I will give that a shot.

If this does not work, I may be looking at an electrode for the unit, which I would be okay with because I know they are a good meter to use. Just would stink because a new Unit I can get for around 70-80 bucks and an electrode is 35-40 (not including a shipping charge if any)

I will post back here when I find out exactly what was going on. I will test with new solution, and then give the electrode a shot if that doesn't work out.


:smoke:

 

[Muddy]

The electrode could just be dirty. If the guy wasn't cleaning it regularly it's quite possible there is a buildup on the electrode. I would suggest getting some cleaning solution and follow the instructions on it first. Once you know it's clean, then recalibrate.

 

[wg]

I've called GH about the shelf life of PH up and PH down because I had some bottles left over when I started growing again. They said as long as they're kept at or around room temperature they last indefinitely. I'd assume the same for calibration solution -BUT- it's less stable because it's a solution loaded with PH buffers to keep a consistent PH to calibrate to. So it's more sensitive to temperature and environment changes. Does it look like it's the same consistency through out? Is it liquid or do you see crystals of any sort in it? Like Muddy, I'd recommend cleaning the electrode first. Check this out; http://www.eutechinst.com/techtips/tech-tips26.htm

Cleaning

The solution used to clean pH electrode depends on the presence of possible contaminants. Mechanically intact electrodes may show slow response due to coating or clogging. Use the guide below to choose the appropriate cleaning solution options:-

For general cleaning: Soak the pH electrode in 0.1 M HCl or 0.1 M HNO3 for 20 minutes. Rinse well in tap water before use.
For removing stubborn deposits and bacteria: Soak the pH electrode in a 1:10 dilution of household laundry bleach for 10 minutes. Rinse thoroughly before use.
For removal of oil and grease: Rinse the pH electrode in mild detergent or methyl alcohol. Wash in water before use.
For removal of protein deposits: Soak the pH electrode in 1% pepsin in 0.1m HCl (EC-DPC-BT) for 5 minutes. Rinse well in water before use.

I'm sure the easiest attainable solution there would be the bleach - give it a go, it can't hurt the meter any especially if it's the electrode. Clean it up, rinse it very well then try calibrating again. Good luck and let us know!

 

[namvet25]

Cockburn (Western Australia) Thats what I got one time from one of my lady friends back in the sixties.:bone::roflcry:

 

[BLACKBRIAR]

I appreciate such a fast response, Thank You Muddy and Whatsgoodie2 - That's the thing, who knows how well he cleaned it, probably not like I would though :/

I am going to soak it in the 1:10 and see where it takes me. It cant hurt, that's for sure. I will follow up here when I get some results.

Happy New Year to you all!

Briar

 

[BLACKBRIAR]

:roflcry: Hahaaaa!!! I didn't want my real location up, so googled funny town names, on the long list that was one, made laugh!

 

[BLACKBRIAR]

Okay I wanted to update here in case anyone wanted to know what panned out.

The TDS/EC Meter was cleaned up, rather easily. I used a 10% bleach solution mixed with water. I soaked it in a shot glass for about 15 minutes. Rinsed and dried lightly. I used my General Hydroponics solution (1500ppm) and it Calibrated Perfectly.

The PH-200 Meter however, I will need to make a decision on what to do. I soaked it, and it seemed to clean it up really nice, but would not take a calibration. Now, this is either the Electrode or faulty/contaminated solution. I do have new 4.0 and 7.0 coming my way so I will give it a shot with new fluid. If not I am most likely buying an Electrode for it.

I did notice though, on the end of the ph meter where the electrode is- there is a glass looking part with a bubble, a white solid piece (I think for temp) and then a clear post with a cork looking substance. If you look REALLY close you can see the inner part of that cork material is all broken down and deteriorated. I think this may be the culprit. I did attempt to get a pic taken, but I cannot get the detail/quality in the photo for you all to see it.

I will give it one last go with new fluid, if not I bite the bullet for $40 and get an electrode. Cant be the batteries as I replaced them. With the $15 in batteries invested, I still think buying a 40 dollar electrode is a smart choice if I have to. A new meter is about $80 for the same. Either that or buy a super cheap ph-meter, Which Id rather not do

 

[BLACKBRIAR]

Alright, this is an update as to whats going on with my PH meter .

It needs an electrode. I tried Brand new solution ,and the unit has new batteries in it. I tested at 4.0 and 7.0.

No dice, reading 9.8 in the 7.0 and about 6.6 in the 4.0.

It wont let me calibrate that far down. I am going to get an electrode and then put a last post up here just to Finalize it.

PPM/TDS Meter on the other hand calibrated just fine. Maybe it has to do with the type of electrode on the ph meter, or bad storage/cleaning habits

I would like to thank those who contributed, especially the information on cleaning the Meter in the 1:10 bleach/water solution. This is something I will be doing to maintain the electrode.

Peace, Blackbriar