A pH buffer is a reference solution of known pH value. These buffers are used for sensor calibration, an essential step in achieving accurate pH measurement results. METTLER TOLEDO offers a broad portfolio of pH buffer bottles for in-line industrial processes and laboratory applications. Single-use sachets are also available to minimize contamination risk in the lab. Whether you need a technical buffer for regular calibration or a high-precision certified calibration standard, we have a suitable pH buffer that meets all your application requirements.
These buffers are designed for user-friendly calibration and maintenance of high accuracy in-line pH measurement systems. Read more
Traceable technical, certified, and NIST/DIN pH buffers ensure accurate pH calibrations in the lab, and are available in bottles or single-use sachets. Read more
pH readings are only as accurate as the solutions used for calibration. Our comprehensive portfolio of pH calibration solutions satisfies every accuracy requirement. Find a suitable pH buffer for every application.
Our DAkkS certified pH buffers are verified by an independent, ISO 17025 accredited laboratory, while the lab NIST/DIN pH buffers are manufactured according to DIN/ISO 19266, offering a low uncertainty (± 0.015 pH). They are therefore a suitable choice for very regulated industries.
METTLER TOLEDO's pH buffers are available in 250mL single bottles and 6x250 six-packs. Our in-line buffers are also in 1L and 5L format. Use lab single-use sachets for easy handling and to reduce the contamination risk.
A lot-specific certificate of analysis is available for every calibration solution, documenting the quality control and accuracy and providing traceability to national metrology institutes. To support compliance with regulations, all SDS (Safety Data Sheet) and labels contain information according to GHS (Globally Harmonized System) in local languages. Read more
A pH buffer is a aqueous reference solution of known pH value.
A pH buffer contains a weak acid and conjugate base, or the other way around, in a certain concentration. This constitutes the buffer system. Any addition of a small amount of even a strong acid or base will have minimal influence on the pH value of the buffer.
The buffers used for calibration must be selected according to the pH of the sample or process.
For instance, if a sample is expected to have a pH of 7.45 or the process to have a pH range of 6.9 to 8.4 the calibration should include pH buffers 7.00 and 9.21 (or similar).
|Use a minimum of two fresh buffers for calibration in the lab and do a two-point calibration in a process environment.
pH Buffers are essential for the adjustment and calibration of a pH sensor to ensure accurate measurement.
It is not necessary to include pH 7.00 for every calibration. The principle is easy: For calibration, only those pH buffers are needed which bracket the pH range of your samples or your process. For example, in a quality control situation where every sample should have a pH between 3.5 and 3.8, a two-point calibration with pH 2.00 and 4.01 is sufficient. There is no need for calibration with pH 7.00 in such a case.
The quality of a pH buffer solution is only guaranteed for unopened bottles that have not yet expired. The following tips will help optimize the use of pH buffer solutions after opening and while in use in the laboratory. Fresh calibration solutions minimize the measurement uncertainty and thus optimize the reproducibility of results:
Note: Fresh calibration solutions minimize the measurement uncertainty and thus optimize the reproducibility of results.
Certificates for all our calibration solutions and many electrolytes can be downloaded at www.mt.com/buffer. The respective material safety datasheets are available at the same place.
The expiry date indicates the date until which the certificate guarantees the value and the associated measurement uncertainty. After this date, the uncertainty cannot be guaranteed, so it is better to discard expired pH buffer.
Never calibrate directly in the solution bottle. Use a fresh aliquot of pH buffer for each calibration to ensure no contamination enters the bottle.
Regular calibrations will lead to more accurate measurement results. Some applications might require a calibration before every measurement, but in general, for laboratory measurements it is enough to calibrate every 24 hours. Always use fresh pH buffers for calibration. In-line measurement is different, the calibration interval depends on the application. Most commonly, the calibration interval is two weeks, but everything from days to even months is possible.