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pH Buffer Calibration Solution Kit 2-Pack — one pH 4.00 (red) and one pH 7.00 (Yellow), Each 250 mL (8.4 fl oz) — NIST Traceable Reference Standards for All pH Meters

  • Based on 328 reviews
Condition: New
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Availability: In Stock.
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Arrives Monday, Nov 25
Order within 21 hours and 57 minutes
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Features

  • Color Coded for Easy Identification
  • Individually Bagged 250 mL (8.4 fl oz) Poly Bottles
  • Lot Numbered and Expiration Dated
  • Free Certificate of Analysis and Traceability
  • For Pharmaceutical, Academic, Research and Industrial Uses

Description

Want that feeling of confidence from doing things right? Get our accurate, unbiased, independent and scientifically documented calibration standards and be sure your meter is working correctly. These buffer calibration solutions are suitable for the calibration of all pH meters. Each production lot is manufactured in our USA laboratory following carefully controlled written procedures and standardized against NIST standard reference materials (SRM) for highest accuracy. The finished product is assigned a unique Lot number and expiration date. These products will have greater than one year shelf life when received.

Brand: Biopharm


Item Weight: 1.41 Pounds


Item Volume: 250 Milliliters


Package Information: Bottle


Item Form: Liquid


Is Discontinued By Manufacturer ‏ : ‎ No


Package Dimensions ‏ : ‎ 9.25 x 4.37 x 2.72 inches; 1.41 Pounds


Date First Available ‏ : ‎ May 5, 2016


Manufacturer ‏ : ‎ Biopharm Inc


Country of Origin ‏ : ‎ USA


Best Sellers Rank: #122,798 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #66 in Chemical Buffers


#66 in Chemical Buffers:


Customer Reviews: 4.6 4.6 out of 5 stars 328 ratings


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Nov 25

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Will be using this from now on
Glad I settled on this one instead of another. I chose this one because of the reviews and that it looks more professional than one of the certain leading brands. Also, there were no complaints about packaging on this item. The bottles are really sturdy and sealed very well. They also come in individually sealed bags inside of a protective cardboard box with the hand-signed lab paperwork. It was pretty much a no-brainer. Worked perfectly to verify calibration of my El Cheapo $10-range pH meter (the generic yellow one you see everywhere). Verified it was calibrated correctly. I will be using this from now on to calibrate instead of powdered formula. When using, make sure that the solution is at 77°F when you're calibrating. Also, take note of the temperatures on the side of the bottle for different pH readings. Mine was too warm so after I poured it into my container I placed it on top of an ice cream carton for a few minutes with the thermometer in it until it was the correct temperature. If you need to warm it up I recommend putting the container in a bath of warm water. To test the meter, I cut a small (clean) ibuprofen bottle in half and put around a tablespoon of solution in there, just enough to cover the electrode. I did this to conserve the solution by using the least amount possible and it worked great. I am confident that this is working correctly because it verified what I already thought was true. ... show more
Reviewed in the United States on August 23, 2017 by Fuzzy Logic Fuzzy Logic

  • Professional or Home Use
This stuff is good enough for professional hydroponic use for any size system. I have a cheap PH meter and a rather expensive one both and it was right on the dot with both. This will probably be my new choice brand from here on out. It's affordable and and accurate to the specific point which is great because there really is no room for error. Comes nicely packaged and contains a report on the fluid from the company. Easy and affordable pro grade, doesn't get much better. 5 stars. *If this helped you could you let me know by hitting the Like button? thanks!* ... show more
Reviewed in the United States on January 3, 2021 by LifePathin4D

  • Excellent product
I ordered these buffer solutions to check the accuracy of a small, inexpensive pH meter I had purchased. In fact the cost of the pH meter and these buffers were approximately the same. But no matter, I wanted to check its accuracy. Although it read correctly on initial testing I observed that on repeated use there was a gradual drift with a positive error of close to 0.2 pH units. On re calibrating the meter the readings on these standardized buffers were again acceptable. Although the pH meter came with packets of buffers that required dissolving prior to use for re-calibrating, it was comforting to have an independent set of standard pH buffers for verification. I am very pleased with them. ... show more
Reviewed in the United States on March 31, 2019 by CessnaPilot95

  • Larger quantity than I need, but does the job
I am a home cheesemaker and one of the things you need to pay attention to when making cheese is the level of acidity of the cheese as it is being made. For that, you need a pH meter and therefore you need to calibrate it on a fairly regular basis. That is where this product comes in. These are certified calibration solutions that you can use on your pH meter to make sure that its readings are reasonable. The product is very simple to use as the bottles are clearly marked and the liquids are colored so you are not likely to confuse the 4.0 with the 7.0. However, given that pH meters do not need to be recalibrated all that often, and that I do not make tons of cheese daily, the quantity of fluid that came in this package will last me for many months - probably far beyond the certified calibration date on it - which is a shame. ... show more
Reviewed in the United States on November 6, 2020 by N. Wallach

  • Works ok
Seems to be a little low on the 4.01 buffer. Maybe a weak bottle?
Reviewed in the United States on January 15, 2022 by M. Hurt

  • Quality
Very impressed on packaging, delivered very tightly packed and cushioned and came with certificate of authentication of pH value.
Reviewed in the United States on August 30, 2023 by Bradley Hamby

  • Accurate down to the exact degree at testing
Products says +- .01 @ 25°c I have verified this to be spot on. Products says +- .01 @ 20°c I have verified this to be spot on. Both the 4.0 and 7.0 buffer reference solutions. Products come with certificates of analysis for both the 4.0 and 7.0 This is now my go to solution. Do not mess with everybody else ... show more
Reviewed in the United States on August 14, 2021 by Choppedncured

  • Works like expected
Works great for my cheap little ph pen. I have some amber 2oz glass jars that I pour this into and then I use that bit for 7-10 days. Hasn’t killed my hydroponically grown ladies.
Reviewed in the United States on September 21, 2020 by kjpen

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