Moisture Analyzers

A moisture analyzer works according to the thermo-gravimetric principle, also often referred to as the 'Loss on Drying' (LOD) principle. The moisture analyzer consists of two components, a balance unit and a heating unit. In order to measure the moisture content the sample's start weight is recorded. Afterwards, a halogen lamp or other infrared radiator heats and dries the sample while the integrated balance continually records the sample weight. When the sample no longer loses weight the instrument shuts off and the moisture content is calculated. The total loss in weight is used to calculate the moisture content.

Our moisture analyzers meet the moisture determination needs of quality control, production and in-process control, offering:
• Accurate and reliable results, through precise temperature control with halogen heating and outstanding weighing technology
• Intuitive operation, with step-by-step user guidance to avoid errors in routine operation
• Consistent measurement performance, thanks to the instrument`s robust design and built-in tests, which are supported by our global service network.

The heating source (halogen lamp, metal rod, ceramic, quartz lamp) and its regulation are defined as a heating system. All mentioned heating sources are infrared radiators. This means the sample is heated by absorption of infrared radiation.

The most important performance factor is precise and fast temperature regulation, which is best delivered by halogen lamps because of their low mass and therefore fast reaction time. This ensures repeatable results starting from the first measurement (some other heating sources either deliver different results in the first measurement or require a warm up measurement, which wastes time and resources). Furthermore, an even heat distribution on the sample surface is essential for repeatable and reliable results. We advise you to ask us or another manufacturer for a demonstration in order to experience the performance in real-life.

Typically, laboratory and production workers require an instrument that is intuitive to use and guides the operators through each process. This ensures that users are following the right procedures thus preventing handling errors. Graphical user guidance, method shortcuts, user management and the ability to select a specific language are helpful instrument functionalities. Watch the video below to learn more about Simple Operation:

We recommend the HX204 moisture analyzer. It contains a high-performance weighing cell with 0.001% moisture content readability separated from the heating source to ensure the best moisture results, even when measuring a substance with very low moisture content.

• Learn more about HX204

Two topics are important with regards to compliance: data management and performance testing. Ensuring data integrity means that every result record needs to be attributable (who has done the measurement), legible (traceable, readable), contemporaneous (recorded at time of generation), original and accurate (correct, complete). Please keep in mind that an instrument is never compliant by itself but it can support the user in being compliant. The HX204 is the moisture analyzer for industries with the highest demands for compliance. It supports the user with safety and data integrity functions such as user management (prevents unwanted changes being made by offering unique user log-ins), tailor-made reporting (including non-modifiable PDF reports) and integrated performance testing of all relevant measuring systems (heating unit, balance, overall instrument test) at the point of use.

• Learn more about HX204

It is possible to control all METTLER TOLEDO moisture analyzers remotely, thanks to the comprehensive MT-SICS command set, which is provided as a standard. However, only the HX204 is suitable for automation due to its automatic lid. This allows you to fully automate moisture measurements, including the selection and initiation of different drying methods.

Replacing your existing moisture analyzer is an important decision. If you have an old  model of moisture analyzer model that we no longer manufacture, then to ensure at least the equivalent performance, we recommend that you consider one of the following moisture analyzers as a replacement to ensure optimal performance:

HR83, HR73 → HX204 

HG63, HG53 → HS153 

HB43-S, HB43, LP16 → HC103

When using a moisture analyzer, it is crucial to maintain consistency in several parameters to ensure accurate and repeatable results that can be integrated into a moisture analyzer method. One of the key aspects is the sample weight. Selecting a specific weight for each sample is essential, as using the same amount each time helps achieve reliable comparisons and prevents variations in measurement that could affect the moisture content results.

Not sure which sample weight is the right one? Ask for a free-of-charge GMAP Recommendation.

Additionally, the drying temperature must be carefully set and standardized for all analyses. The temperature can significantly influence the rate at which moisture evaporates; if this parameter varies, it may lead to inconsistent results across different determinations. The drying mode is another important factor to consider. Many moisture analyzers offer different modes, such as standard for solid or rapid drying for liquid samples, which can impact the efficiency of moisture removal. Choosing a specific drying mode and using it consistently enhances the reliability of moisture content readings. Finally, the switch-off criterion should be consistently applied. This criterion defines when the drying process should end, often based on a specific weight loss over time. Using the same switch-off criterion ensures that all samples are analyzed under the same conditions, further enhancing the accuracy and comparability of the moisture content results. All METTLER TOLEDO moisture analyzers offer automatic switch-off criteria. By focusing on these parameters—sample weight, drying temperature, drying mode, and switch-off criterion—you can achieve precise and consistent moisture measurements across different samples. With the Excellence moisture analyzer, even more method parameters for specific samples, such as volatiles or very low moisture contents, can be applied.

You can find more information in our Guide to Moisture Analysis.

The Method Wizard is a feature of HC103, HS153, and HX204 that offers assistance in developing a suitable moisture method for specific samples. Based on the characteristics of your sample as well as a test of the drying temperature and switch-off criterion, the Method Wizard can formulate a suitable method for your sample. The Method Wizard guides you through the development of your moisture method in three simple steps:

1. Questionnaire: proposal of method parameters based on sample characteristics. 
2. Temperature assistant: determination of drying temperature. 
3. Test measurement: verification of temperature and selection of appropriate switch-off criterion. 

After each step of the Method Wizard, you can decide whether to accept the current method settings or to complete another step of the wizard. For steps 2 and 3, a reference moisture content value is needed. 

Watch the video for more details:

All METTLER TOLEDO Moisture Analyzers measure a minimum recommended moisture range of 1%MC, with the HS153 capable of measuring down to 0.5%MC, and the HX204 reaching as low as 0.01%MC. In addition to measuring low moisture content in solid samples, these analyzers can also assess liquid samples. Special drying modes, such as “Rapid,” enhance the drying process. The use of consumables like glass fiber filters not only increases the surface area for a more homogeneous sample distribution but also prevents film buildup and reduces measurement time. Thus, the moisture analyzer is versatile enough for liquid, slurry, paste-like, and solid samples. Users can also select the desired result unit, such as moisture content (%MC) or dry content (%DC).

Moisture analyzers are effective tools for measuring moisture content in various substances; however, special care must be taken when dealing with volatile compounds. Depending on their characteristics (e.g., flammable), a risk analysis should be conducted to evaluate if the moisture analyzer is the right choice. These volatile substances can evaporate during the drying process, depending on the selected parameters. The specific drying program “Gentle” is designed for the drying of substances that tend to form a skin, such as those containing sugar, or for substances with highly volatile components. This program features a continuous temperature increase that reaches the selected drying temperature only after a predetermined ramp time. The ramp time is the interval between the start of drying and the achievement of the final temperature, which can be set in advance. For samples that contain readily evaporating substances, it is advisable to use the manual starting mode. Unlike the automatic operating mode, where the start weight is determined with a closed lid, the manual mode allows the sample chamber to remain open and detect the start weight immediately. This ensures that the initial weight is recorded without any loss, preventing inaccuracies before the measurement begins.