Outlining the different applications of Moisture Analysers and Water Activity Meters within the food industry.

A common misconception within the food industry is that Moisture Analysers and Water Activity Meters are essentially the same piece of kit. The Klipspringer team are eager to dispel this myth, as confusion could lead to a site investing in the wrong equipment. It could also result in a factory budgeting for just one purchase, when in fact both systems need to be accounted for. Our experience supporting the food industry for nearly 22 years has taught us that if a site needs a Moisture Analyser, it will often require a Water Activity Meter as well.  

With this in mind, we wanted to share the different applications of each piece of equipment. Hopefully our comprehensive overview will help you to decide which option is best suited to your site: the Moisture Analyser, the Water Activity Meter, or both. 

Below is a list of the questions we will be answering in this overview. We would be happy to guide you through each point, but there is also the option of skipping to the section most relevant to you.

Moisture Analysers

As the name suggests, a Moisture Analysers detect the moisture content of a substance. This piece of equipment is commonly used to test building supplies, agricultural resources, and cosmetics.  

Moisture Analysers also play an important role within the food and beverage industry. Below are just a few examples of products that are tested by this piece of equipment. As you will see, the list includes liquids, pastes, and solids.

  • Milk 
  • Fruit Juice 
  • Tea and Coffee
  • Meat
  • Ketchup
  • Yoghurt
  • Bread  
  • Biscuits  
  • Flour 
Moisture Analysers

Moisture impacts the way a product looks, tastes, feels, and even smells! A good example of this is the chocolate chip cookie, with moisture playing an essential part in its crunchie and chewy texture. If a site wants to drive quality control and consistency, a Moisture Analyser is the best way to eliminate guesswork.  

This useful piece of equipment can also be used to drive food safety, with many factories measuring the moisture levels of items such as bread and biscuits to find out if they are vulnerable to microbial growth and contamination. This information is then used to extend the shelf life of a product.  

Finally, depending on the specific needs of a factory, a Moisture Analyser can help it to either save money or strengthen customer relationships. Moisture is often seen as an inexpensive yet effective way to add weight to a food or beverage. Being able to do this accurately will help a site to produce a product with all the essential attributes, but at a slightly lower price point. Alternatively, Moisture Analysers can be used to ensure customers aren’t overpaying for water weight.  

How do you use a Moisture Analyser?

Moisture Analysers
  1. Lift the lid and place your sample inside the metal pan
  2. Select the relevant pre-saved test program
  3. The Moisture Analyser will now weigh your sample
  4. Once the sample has been weighed, the unit will heat and dry the sample until the moisture has evaporated
  5. The Moisture Analyser will now weigh the sample again
  6. The second weight is automatically subtracted from the first
  7. The result of this equation determines the loss of mass and, by extension, the loss of moisture

What should you look for in a Moisture Analyser?

An automatic test-setting function 

It is common for a factory to repeat tests, with operatives often carrying out the same processes multiple times a day. An automatic test-setting function will save your workers a lot of hassle. Here at Klipspringer, we are proud to supply the PMB Moisture Analyser. One of the main reasons for us giving this model our seal of approval is the fact that it stores 49 different recipes and 99 test results, with the option of storing additional settings and test results on a flash drive. 

Moisture Analysers

A variety of heating options 

If your site needs to customise test methods and temperatures, it’s important that your Moisture Analyser has a variety of heating options. This is true of the PMB Analyser which has three settings for heating: ramp-up, stepped temperatures, and single temperature. It also has four pre-set drying modes, along with a temperature range of 50°C to 160°C that can be adjusted in one-degree increments. 

Moisture Analysers

A smart approach to data sharing 

The time-saving benefits of a speedy moisture reading will be undermined if the process of sharing the results is slow and clumsy. That is why you should evaluate the way in which your Moisture Analyser shares data. The PMB, for example, includes two USB ports (one for data collection and one for communication with a PC or printer). It also has one RS-232 port, a USB I/O interface, and a USB host for a memory card. 

Moisture Analysers

A durable design 

Finally, you should be on the lookout for a durable design that holds up against daily use. The scratch-resistant aluminium housing of the PMB will protect the more vulnerable internal components of your Moisture Analyser. The unit also has a security slot that can be linked up to an optional lock and cable to protect against theft.

Moisture Analysers

Key Features of the PMB Moisture Analyser

  • Temperature range 50°C to 160°C in one-degree increments 
  • Capacity tracker built into display for easy monitoring of possible overloads 
  • Internal memory stores 49 different recipes and up to 99 test results* 
  • Scratch-resistant aluminum housing 
  • Pan lifter allows easy placement and removal of samples   
  • Four preset drying modes allow test routines for several products 
  • Security slot for optional lock and cable to help prevent theft 
  • RS-232 interface provides speedy connection to computers and printers 
  • USB interface included for data communication 
  • Three settings for heating: ramp-up, stepped temperatures, and single temperature 

* additional test results and settings can be stored on a flash drive

Water Activity Meters

A Water Activity Meter measures the amount of unbound (or free) water in a product. Water activity is essentially the way in which the water in your food reacts with microorganisms like bacteria, yeast, and mould. Also known as the aw value, it is the ratio between the vapour pressure of water in a test sample and the vapour pressure of pure water at the same temperature.   

Below are just a few examples of products that are tested by this piece of equipment. 

  • Butter 
  • Fruit mix 
  • Spices 
  • Mushrooms 
  • Flour 
  • Biscuits 
  • Sausages  
  • Cheese 
  • Honey 

It is also worth noting that Water Activity Meters are unsuitable for juices (syrup), food and beverages containing alcohol, and acidic foods such as vinegar.

Water Activity Meters

Water Activity Meters help sites to determine the shelf life of a product and work out how it is going to be stored. For example, foods with a high aw value such as fruits and vegetables, will be more susceptible to spoilage and deterioration. This will result in the close monitoring of their environment, and will also indicate a much shorter shelf life. In contrast, dried foods are more likely to be handled in a low risk factory zone and boast a significantly longer shelf life. 

Water Activity Meters are also commonly found at meat factories, often used to indicate if a piece of meat is over or under cooked. They are also of great value to sites that handle fresh meat, as meat in this form has the highest levels of water activity and is therefore most susceptible to the growth and survival of harmful microorganisms. 

How do you use a Water Activity Meter?

  1. Connect the unit to the device 
  2. Turn on and navigate to the Water Activity Measurement function
  3. If the environment is different to where the sensor has been stored, wait 30 minutes for it to adjust to the new temperature 
  4. Fill at least two thirds of the jar, ensuring the product doesn’t touch the protective metal grid 
  5. Seal the jar and wait for the reading to stabilise 

When it comes to understanding the results shown by your Water Activity Meter, you need to remember the following:

A high reading: harmful microorganisms will thrive and spoil the product

A low reading: only non-harmful microorganisms can grow

An incredibly low reading: barely any microorganisms will grow

What should you look for in a Water Activity Meter?

A generous measuring chamber 

To ensure your Water Activity Meter is driving efficiency, it needs to be able to measure high quantities within a short period of time. Otherwise, your operatives will be left waiting around for the equipment to become available or will be unable to test the desired sample size in one go. To avoid this, you will need to invest in a Water Activity Meter with a generous measuring chamber that is capable of holding a large sample volume. This requirement was a driving factor behind our decision to supply the Humimeter RH2 Water Activity Meter, as this model is compatible with both 186 ml and 245 ml measuring chambers.  

Water Activity Meters

Ease of data sharing 

Once you are happy with the way in which your Water Activity Meter generates results, you should also evaluate the options it provides for sharing them. For example, the Humimeter RH2 allows you to transfer results onto your devices via a Bluetooth connection. This connection can also be used to send them directly to a printer. In addition to this, you can auto-save measurements at specified intervals for future reference and can set the device to manually record results. 

Water Activity Meters

Protective casing

As with Moisture Analysers, you need to prioritise the durability of your Water Activity Meter. Otherwise, you will be unable to make the most of your investment. Aware of this requirement, the Humimeter RH2 comes with a protective case, along with a sturdy rubber sleeve that will hold up against the wear and tear of factory life.  

Water Activity Meters

Key Features of the RH2 Water Activity Meter

  • Integrated fan to regulate air circulation 
  • Portable handset 
  • Long-term, stable humidity and temperature sensors 
  • Easy data storage on the portable moisture meter 
  • Memory function: online, hold, or manual data log 
  • Datalog for 10,000 values with measuring point report 
  • Optimal documentation of quality levels 
  • Fast paced adjustments 
  • Large water activity measuring chamber for higher quantities

What are the benefits of having both a Moisture Analyser and a Water Activity Meter?

First, we would like to be upfront about the fact that we supply both the PMB Moisture Analyser and the RH2 Water Activity Meter. We hope that our time supporting over 4,000 customers within the food and beverage industry reassures you that our intention for recommending the use of these devices in tandem is entirely genuine and informed by nearly 22 years of experience.

Moisture Analysers detects the moisture content of a product. It is typically used to achieve consistent results and to establish a workable recipe – helping you to understand the exact amount of water in your ingredients and final product. It’s true that this piece of equipment can also indicate if there is enough moisture to support microbial growth and unfortunately, this is the point at which some sites prematurely rule out the use of a Water Activity Monitor, believing the Moisture Analyser will tell them everything they need to know.

This is simply not the case. Although Moisture Analysers can tell a factory if its product contains enough moisture to support microbial growth, it’s the Water Activity Monitor that reveals exactly how this moisture is going to react with mold, mildew, and other contaminants. This second piece of kit will help you to determine the storage requirements and life span of your products and ingredients.

In Conclusion

Moisture Analysers

A Moisture Analyser detects the moisture content of a substance. It weighs a sample, evaporates the moisture, then re-weighs the sample. The second weight is subtracted from the first to work out the amount of moisture that has been lost.

Water Activity Meters

A Water Activity Meter measures the amount of unbound (or free) water in a product. It works out the ratio between the vapour pressure of water in a test sample and the vapour pressure of pure water at the same temperature.   

That brings us to the end of our overview of the differences between Moisture Analysers and Water Activity Meters. We hope that you can now see why it is so important to establish a clear distinction between the two pieces of equipment – understanding their individual features and functions.  

We also hope that our guide has helped you to identify any special features that could bring value to your site. Here at Klipspringer, we supply both the PMB Moisture Analyser and the RH2 Water Activity Meter, so we would be happy to help you with your enquiries if you require any further support. You can also view the devices on our website by following the links below. 

If you would like further guidance relating to Water Activity Meters and/or Moisture Analysers, the Klipspringer team would be happy to help. Share your details below to arrange a free consultation.