HI-7004L – pH 4.01 buffer solution, 500ml bottle
The pH 4.01 buffer is available in a 500ml bottle, one of the most commonly used buffer solutions. It is extremely stable and represents the mid-way point in the acid range of the pH scale – ideal for those requiring an accurate acid reading, particularly those working in water purification plants, the food industry, and wherever the pH is expected to be acidic.
Buffer solutions should be stored at 25◦C, away from direct sunlight for accurate readings.
To correctly maintain your meter/electrode, we highly recommend use of a Hanna cleaning solution, as well as a buffer, for maximum performance every time. pH4, along with pH7, can also be used as an emergency storage solution.
Hanna buffer solutions are prepared, ready-to-use, according to precise formulas and standardised in accordance with the National Institute of Standards and Technology (NIST) to ensure quality and accuracy. All solutions show a batch number, an expiry date, and the correlation table between pH and temperature. A certificate of analysis is available on request. All bottled solutions are sealed with an air tight, tamper-proof seal to prevent any Carbon Dioxide from entering and causing a change in the pH buffer value.
Browse the Hanna complete range of solutions
- pH buffer solutions
- Standard solutions for conductivity, Total Dissolved Solids (TDS), turbidity, salinity and Ion-Selective Electrode (ISE) calibration
- Oxidation Reduction Potential (ORP) test and pre-treatment solutions
- Reference fill solutions for refillable electrodes
- General and specific cleaning solutions for electrodes
- Solutions for electrode maintenance and storage
- Solutions for sample preparation
Solutions are available in many sizes ranging from 20ml sachets for small users to 3.78L (1 gallon) containers for large quantity usage in laboratories.
For safety and traceability, all Hanna solutions are provided with a label showing the batch number and expiry date. A certificate of analysis is available on request in line with NIST standards.
- Calibration only counts when using fresh solutions and properly cleaned electrodes every time.
- Routine maintenance will ensure accurate readings while extending the life of the electrode.
Colour Coding for 1L and 1 gallon bottles:
- pH 4.01 – Red
- pH 7.01 – Green
- pH 10.01 – Violet
All calibration buffers are made to a premium quality, produced in accordance with ISO 3696/BS3978 standards using high purity salts, deionised water, certified weight-checked balances, and Class A glassware in a temperature controlled environment monitored with certified thermometers.
All bottles meet with FDA Standards (US Food and Drug Administration).