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PH pen third party calibration buffers

MrClockOff

Member
Joined
20 Aug 2020
Messages
342
Location
Bridgend
Hi all,

I’m new happy owner and user of Hanna PH checker HI-98103.

I’m looking for buying spare 4 and 7 PH calibration solutions. The original Hanna solutions are only being sold in 0.5 litres containers for about £30 per bottle.

I can find cheaper third party solutions and in smaller containers but for some reason they are 4.01 and 7.00 where original are 4.01 and 7.01. Is it important to use 7.01 PH solution or 7.00 PH is equally fine?

Many thanks
Daniel
 
Hi @MrClockOff

I use the Milwaukee pH 4.01 and pH 7.01 calibration buffer solutions. They measure 4.01 and 7.01 at 25C. But this equates to 4.00 and 7.03 at 20C. The slight variation of pH with temperature is very unlikely to give you any cause for concern. But, please feel free to get a second opinion! I like to use 20 ml buffer sachets - use once and then throw away.

JPC
 
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I have the combo meter, and the only one I use the Hannah branded calibration solution is for TDS, since the calibration point is preset.
 
Hi all,
I use the Hannah branded calibration solution is for TDS since the calibration point is preset.
What is the calibration value? and is it in micro S? and if it isn't? Does it have a conversion factor listed?

They may sound strange questions, but while the buffers for pH are quite complex to make up, the calibration standards for conductivity (TDS) meters are <"really straight forward to make">, and you only need kitchen scales. I make a stronger stock solution and then use <"serial dilution for the standard">.

cheers Darrel
 
The calibration value for the HI 98129 is 1413 us/cm. That's obviously much higher than my water, so I use that one to set the calibration, and then verify with an external standard @ 23 us/cm. It's a good idea to make my own KCl solution, but I wonder if I can be precise enough for the lower value. I could try it. I also think it will take a very long time to run through my premade standards. The TDS calibration stays pretty true.

The unit does have a TDS readout, but their conversion is 0.45, not 0.64. So I just record the conductivity for my notebook.

Cheers
 
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