The pH 4.01 buffer is available in a 230ml bottle, one of the most commonly used

The pH 4.01 buffer is available in a 230ml 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.