What is an infrared moisture meter? An explanation of its non-contact method of measuring moisture, including its principle, calibration curve, and measurement points.

Measuring moisture using infrared light

Water has a property that makes it easily absorption infrared light of specific wavelengths. Infrared moisture meters utilize this property to measure changes in the optical information obtained from an object.

Measurement can be taken without contact with the object.

In methods that utilize infrared light irradiated onto an object and the reflected light, measurements can be taken without the sensor directly contacting the object.

Therefore, it can be used when you don't want to affect the object by contact, or when you want to measure an object that is moving along a manufacturing line.

It is positioned as one of the methods for measuring moisture.

There are various methods for measuring moisture, including the heat drying method, the Karl Fischer method, and methods that utilize electrical properties. Infrared moisture meters are one such method that utilizes the interaction with light and electromagnetic waves.

• What is moisture measurement? Typical measurement methods and how to choose the right one.

Water has wavelengths of infrared light that it easily absorption.

Infrared radiation has various wavelengths. Water does not absorption all wavelengths equally; rather, it absorption different wavelengths differently.

Therefore, by utilizing wavelengths that are easily affected by water, it is possible to obtain information about moisture content in the object.

The optical response changes depending on the amount of moisture

When the amount moisture contained in an object changes, the degree to which the water absorption infrared radiation also changes. As a result, optical information such as the intensity of detected light also changes.

There is a method that utilizes the measurement wavelength and reference wavelength

In actual measurements, instead of just looking at wavelengths that are easily affected by moisture, there are methods that combine wavelengths for comparison and other factors to capture changes related to moisture.

This allows us to extract optical information related to moisture while distinguishing it from changes in light intensity itself.

• What is infrared measurement? It's a mechanism for measuring temperature, moisture, constituent, and thickness.

The optical signal itself is not the water content.

The sensor directly detects the intensity of infrared light and the optical response for each wavelength. This signal itself does not directly indicate "5% moisture," for example.

The actual moisture content is determined using a standard method.

First, moisture content of the object to be measured is determined using a standard method appropriate to the purpose, such as the heat drying method.

Determining the relationship between optical signals and reference values.

For multiple samples with different moisture content, we correlate the optical measurements taken using infrared light with a reference moisture value.

This allows us to examine the relationship between changes in optical measurements and how moisture content changes.

Use calibration curve to convert to moisture content.

A "calibration curve" is a representation, often expressed using mathematical formulas or graphs, that shows the relationship between optical measurements and actual moisture content.

In actual measurements, the optical information obtained from the sensor is applied to this relationship to convert it into a moisture value.

It captures light that results from the interaction between infrared radiation and an object.

Infrared moisture meters detect optical information obtained as a result of absorption and reflection of infrared light irradiated onto an object.

The part being measured is not necessarily the same as the entire object.

The information obtained by the sensor reflects the state of the area where infrared light is actually irradiated and detected. Therefore, it is necessary to consider to what extent the measurement area represents the state of the entire object.

The uniformity of the object is important.

If moisture, particle size, density, surface condition, etc., vary significantly depending on the location of the object, the values obtained may change depending on the measurement location.

When installing a device in a manufacturing process, it's important to consider not only ease of measurement but also whether the location provides information representative of process.

Measurement can be taken without contact with the object.

Because the sensor does not directly contact the object being measured, it can be used to measure moving objects such as paper, sheets, food, and powders.

It can measure moving objects.

If you can measure the substances flowing through the manufacturing line, you can understand the changes moisture during process, which is difficult to obtain by simply taking a sample and measuring it.

Data can be acquired continuously.

By continuously acquiring moisture levels, you can observe changes and variations over time.

Measurement values can be used for recording and monitoring.

By recording moisture levels and monitoring them in conjunction with process conditions, you can use this information to understand and review process status.

The roles of online measurement and sampling measurement, as well as their use in measurement locations and process control, are explained in detail in "moisture Measurement in Manufacturing process."

• What is moisture measurement in the manufacturing process? The concept of online and continuous measurement.

What are we measuring?

We check the type, shape, state, and composition of the material. Even with the same moisture content, the optical information obtained may not be the same if the objects are different.

What range of moisture should be measured?

We will first determine the expected moisture range and then evaluate the relationship between moisture and the optical signal within that range.

How do you determine the standard moisture content?

To create and verify calibration curve, a reference moisture content is needed. We will determine the appropriate reference measurement method for the sample.

Will product and composition change?

If product, composition, or raw materials change, we will check whether these differences affect the optical measurements or calibration curve.

Where will it be installed?

The installation location is determined by considering factors such as the distance between the sensor and the object, the movement of the object, the representativeness of the measurement location, and the surrounding environment.

What will the measurements be used for?

Clearly define the purpose of using the measured values, such as quality control, recording, monitoring, and process condition verification. The required measurement accuracy and system configuration will vary depending on the purpose of use.