hanna phep 5 calibration error

Assuming you have put the electrode in correct solutions as asked by the display content - something went wrong in the second solution. I don't know Hanna meters, but it is very unlikely to me that they don't show error message at once after dipping electrode into pH 7.01 solution - pH meter must recognize the solution before moving to the next one.

Do you have pH stripes, to check if the second solution pH is really around 4 (and the first one around 7)? Don't bother with high accuracy, just check if they are around their proper values.

Borek

Maybe the probe needs replacement?

This makes me raise a question I was wondering about. Keep in mind I'm small hobbist wine maker and a cheap skate. I've heard that you can use 2 common household items with a PH at approx 7 and 4 instead of the calibration packs. The hanna ph meter reads to 0.01 but is only accruate to plus/minus 0.2. So very good accuracy of the test solution isn't that important. A bottle of water (not tap) would work for the 7 range. Any ideas what could work for the higher acidic range? Windex, dish soap, Coke or Pepsi?? I guess you'd have to know what the PH of each was before you calibrate.

water is not a good buffer, if you want something close to 4 try cream of tartar at 3.54 pH. Cheap buffers can be had from Hydrion. This meter is accurate to 0.05.

As to the OP, email Hanna, they are good at customer support. I have this meter and never had this issue, mine is around 5 years old.

Joe

Between 5.5 and 6, distilled water gets saturated with CO2 very fast and becomes acidic.

Borek

Spend the $8 and buy some new, accurate buffer solutions (Presque Isle has them). They are stable for a pretty long time - afterall, they are buffers. The pHEP5 is accurate to 0.05 units, as Joe mentioned, so I think you'll waste more than $8 in time and frustration seeking household items as pH standards.

pH 4 buffers are stable, pH 7 more or less stable, pH 10 buffers are unstabel if they are not kept airtight. Once again that's CO2 in action.

But you are absolutely right that it doesn't make sense to look for household items, as relatively precise buffers can be bought cheap.

Borek

That doesn't work if you can't set the calibration value on the meter to what the pH of yout household item "buffer" is - for example, for cream of tartar solution you'd need to set the calibration point of the pH meter to 3.53-3.55 instead of 4. You can't do that on pHep 5.

Where the cream of tartar can come in useful is in checking the accuracy of the calibration. I ran into this actually on the weekend because my buffers are well past the expiry date on the label, so I measure a cream of tartar solution after calibration to make sure I wouldn't dump in tartaric acid into a wine that didn't need it. It measured at 3.55 so spot on.

Pp

I had no plans to make my own calibration solution.

I ordered new solutions, probe storage solution and a new probe.

My plan tonight. Make new solutions and check old probe.

If it still has the error message then replace the probe and retest.

pp wrote:

I used my Hanna buffer sachets 4.01 and 7.01 Meter gave the same error on calibration.

I changed the probe

Now it calibrates fine with no errors....

I also bought some pH storage solution. Hopefully I get more then 2 years on this probe.

Borek wrote:

If you don't have storage solution you may use pH 7 buffer, the one used for calibration. pH electrodes have limited lifespan, they are rarely working than about a year. Sure, you may be lucky to have one that survives longer ;)

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Borek