pH Measurement in Laboratories: What You Need to Know

Although the science behind pH testing may be complicated, the idea at the heart of it all couldn’t be more straightforward. The term is used to describe a very precise numeric scale that itself specifies the acidity or basicity of any aqueous solution you’re working with. The scale runs from 0 on the low end all the way up to 14 on the high end. If a solution is tested and comes in lower on the scale, it is therefore more acidic. If it comes in higher on the scale, it is more alkaline (or “basic”).

pH levels can ultimately have a major impact on someone’s health, which is why they’re monitored so closely – particularly in the food and beverage industries. When discussing our drinking water, for example, the Environmental Protection Agency requires all water to be kept in a range of between 6.5 and 8.5 on the scale. This is because without regulation, drinking water that is too acidic or alkaline can have potentially harmful impacts on someone’s health.

pH Measurements and Our Health

Indeed, the potential impacts of substances with certain pH levels on our health are among the myriad reasons why pH measurement is so important to laboratories around the country. To continue with the example of drinking water, consider that water below a pH level of about 7 naturally has a corrosive quality to it. This means that the levels of iron, copper, lead or even zinc in that water are far too high for someone to consume – thus making even a normal glass of water more dangerous than it appears.

Knowing the pH level of water can also help shed insight into problems located elsewhere within an environment. If there is too much iron in drinking water, this could be a sign that plumbing and other metal fixtures may have begun to corrode.

Generally speaking, the first sign that something is wrong would be a glass of water that has a metal or bitter taste to it. If water has too much alkaline, it will likely taste like baking soda. While high-alkaline water doesn’t necessarily pose any serious health risks like its acidic counterpart, it CAN contribute to the formation of scale, which is why it’s always so important to be aware of.

The Impact on What We Eat

The pH of substances has other implications, too – particularly in terms of what we eat. pH levels are regularly taken in laboratories in the food and beverage industry to determine the quality of meats, for example. If you take the pH measurement of pork and it comes in at around 5.5 to 6.0, it’s a good indication that the pig in question was raised well and that it lived a relatively stress-free life. If the pH is between 4.9 and 5.5, however, this could indicate that the pig was raised poorly – or that it had experienced stress.

The same type of information can be obtained by taking the pH level of cheese. Generally speaking, most milk falls within a range of 6.5 to 6.7. If the pH reading of cheese (which is made from milk) comes in above those levels, it could indicate that the cow the milk was obtained from had some kind of illness. Values below that range could indicate that the process of lactic acid fermentation has started. pH levels will even impact whether the cheese is crumbly, solid or devoid of any shape entirely. All of this is actionable information that food and beverage processors can use to not only make the right decisions for their customers moving forward, but make the safest possible decisions, as well.

pH Measurement in Laboratories

The hardworking men and women in laboratories use a wide range of different techniques for fast and accurate pH measurement, including, but not limited to, pH indicators, pH test papers and pH meters.

pH indicators are interesting because they’re actually liquid. They normally have a precise pH range, and if the liquid they’re poured into falls within that range, they will change colors accordingly. This is an efficient technique if you already know a bit about the substance you’re working with – they’re less helpful if something falls outside the given pH range.

pH test papers are often a special type of litmus paper designed to broadly test where a solution falls on the scale. They typically come in three main types – blue, red and neutral. A blue pH test paper will turn red in the presence of an acidic solution, while a red test paper will turn blue in the presence of a base. Neutral test papers will then turn red OR blue depending on the nature of the solution. There are also more precise pH testing papers available that can not only find out where something falls on the scale, but can do so down to an accuracy of about 0.2 pH units.

pH meters are by far the most accurate of the options, as they give laboratory workers the most actionable information to work from. When a solution is analyzed, the meter will actually analyze the difference between a pH electrode and a reference electrode. At that point, the meter converts the results into a pH reading – usually with an accuracy of about 0.01 pH units. These are ideal when an intense level of precision is required and, because of that, are the most common tools found in laboratories. pH meters come in handheld and portable meters, too, making them ideal for field or remote work.

Learn About Weber Scientific

For decades, the team at Weber Scientific has made it a priority to stock only the highest quality products for your laboratory, manufactured by some of the most-trusted names in the industry today. Whether you’re in need of high-quality pH testing equipment or just need to stock up on critical supplies, we have everything you need and more – all at the types of competitive prices you won’t find anywhere else.

If you’d like to find out more information about the importance of pH measurements in laboratories, or if you run a lab yourself and would just like to discuss your needs with someone in a little more detail, visit the Weber Scientific website today.