15-Pack pH Meter Buffer Solution Powder for Precise and Easy PH Calibration, PH Calibration Powder Solution 6.86,4.01,9.18

These buffers are easy to use because the instructions are clear and the reference values are provided on the back of the sachet. A single sachet lasts me for half a month in refrigeration using small portions to calibrate my sensor controlled by a micro controller. Recommended for use with any type of pH sensor!

The instructions must be followed precisely. Even the temp of the test water makes a difference. If your distilled water is not at 77 degrees, you need to adjust for that. We found that even if the ph tester says it can adjust for water temp, it will probably not, at least the first time you calibrate it. It took us a couple of times to realize that we could not compromise even the smallest. If it says 750ml of test water, it means exactly that, 750ml, not alittle less or more. If you follow the instructions, these will work well for calibration of your meter.

Sometimes cloudy looking and sometimes not? Was able to calibrate with it.

These work great for making standard pH testing solutions to calibrate your lab meters. For the money you cannot beat these. I have had great luck with using these to test and calibrate my pH meters in my lab. Don't forget to use ionized water.

These are packets of calibration medium that I need to recalibrate my meross ph meter. They arrived ahead of schedule and are exactly what I ordered and need for calibration. They should work exactly as those enclosed in my new ph meter for it's initial calibration as they are the same size and brand, so I'm ready for any needed recalibration.

I tried to calibrate my pH meter with all 3 levels of these pH calibration packets, but when I tested it on those solutions again after calibration, the pH meter readings were off by more than 0.1 pH. So I tried calibrating the meter a 2nd time with the same solutions, and then when I tested the meter on those solutions again, it gave results that were off by no more than 0.02 pH, which is accurate enough for my purposes. The meter readings seem to be fairly consistent with the results from my API Master Test Kit.

They do as they're advertised to do

I mean how do you review of product like this unless you test it and compare it to another brands of meters to know if it's accurate or not. I'm sure it's accurate but it is kind of a pain in the @ss to have to calibrate it every so often with distilled water and not knowing when it needs calibrated unless you have another one to compare it to that tells you to calibrate it.