A halogen moisture meter is also called a halogen moisture detector. A fast way to find moisture is with a halogen electronic moisture meter. It uses a high-precision electronic balance based on the principle of electromagnetic force balance.
It also has an annular halogen lamp and a mirror reflector, which make it possible to figure out the sample’s moisture content quickly, steadily, and accurately. A halogen moisture analyzer can be used to find moisture in medicine, plastics, chemicals, food, surimi, dehydrated vegetables, macromolecule materials, carbon fiber, noodles, flour, biscuits, mooncakes, grain, fodder, seeds, solid content, rapeseed, tobacco, tea, textiles, agriculture and forestry, paper making, rubber, textile, powder, and other samples.
The halogen moisture meter uses the “loss on drying” method and heats the sample quickly with the heating system. This quickly evaporates all of the sample’s moisture so that the moisture content of the sample can be found in a very short time. During the drying process, the rapid moisture tester keeps track of how much moisture the sample has lost and shows it right away.
After the drying process is done, the final value of the moisture content measurement is locked and shown. After preheating, it only takes more than 40 seconds to heat up to 50–180 °C, and it only takes a few minutes to accurately measure common materials. The wavelengths of 95 percent of the light emitted by a halogen lamp are in the infrared range, and its energy is nearly identical to that of an infrared lamp, heats faster and costs less to maintain than an infrared lamp.
The significance of measuring moisture with a halogen moisture meter
- Moisture is one of the important quality indexes.
Foods that have the right amount of moisture can keep their quality and last longer. All kinds of food have their own rules about the amount of water they use. If the moisture content goes up or down by 1 percent, it can have a big effect on both the quality and the cost. For example, bread and cookies get harder not only because they lose water and dry out, but also because the way water changes the structure of starch.
Also, the taste of processed meats like sausage is closely linked to how well they absorb and hold water. So, the amount of water in food is a very important factor in many ways, such as its freshness, hardness, softness, fluidity, flavor, ability to last, be processed, and so on.
- The amount of water is a key economic indicator.
Depending on how much water is in the raw materials, food factories can balance the materials. For example, if the material balance calculation is done first, how many kilograms of water are needed to make 100 kilograms of noodles? The amount of water in dough affects how well it sticks together. When the dough is soft, more water is added. When the dough is hard, less water is added, and the volume of bread is small, which changes how much money can be made.
The content of water has a lot to do with how microorganisms grow and react biochemically.
In general, to stop microbial growth, you need to control the lower water content, but the lower the water content, the better. Most of the time, biochemical action is weaker than microbial action. From the three points above, we can see how important it is to measure moisture, which is a key part of our food analysis.
Comparison between the halogen moisture meter and the oven method
Drying things in an oven is the traditional way to measure moisture. It takes two, three, or even four hours to test a sample. In order to measure the sample, it must be taken out of the oven every 30 minutes and weighed on a precision balance. If the weight of the sample doesn’t change after being weighed twice, it means that all of the water has been dried.
The sample’s water value (moisture content) can then be found by putting it on a scale and doing some math by hand. The oven method is used to figure out how much water is in a sample because it is more accurate. The problem is that it isn’t very good at what it does and can’t keep up with the needs of fast-paced business production.
The halogen rapid moisture tester uses a high-quality annular halogen lamp’s drying heater to heat and dry a sample quickly and evenly. The sample’s moisture is dried continuously. During the whole process of taking a measurement, the instrument shows the sample’s weight, the amount of water and solids, the measurement time, the heating temperature, and more.
The rapid moisture tester is based on the way an oven dries things. The results of the measurements match up well with the oven method’s measurements of moisture, but the working efficiency is much higher than the oven method’s. With the rapid moisture tester, a general sample can be measured in just a few minutes. Because of this, it is now used more often.
Difference between halogen and infrared moisture meter
Different heating methods
- The infrared heating method is adopted for the infrared water heater. Because the infrared heating lamp is spherical, there is a spotlight in the heating process, and there will be a little color change in the middle of the measured sample, but it will not affect the final test results.
- The halogen moisture meteradopts a halogen heating mode, and its heating source is a halogen heating lamp. Because the halogen heating lamp is a special ring, in the process of heating the test sample, the heating surface of the sample is uniform, and the measured sample has no change, so its stability is better.
Comparison of halogen and infrared
- Halogen lamps have a long service life and a high calorific value.
- Halogen uses an annular heating tube so that the sample can be heated more evenly in the test process.
- Halogen lamps contain inert gases.
Halogen heating moisture meter vs Karl Fischer moisture meter
Most of the time, the Karl Fischer method and the heating weight loss method are used on the market to figure out how much water something has. This method won’t work in the lithium battery business because the samples have very little water in them. The heating weight loss moisture meter can’t be made to work correctly, so this method can’t be used.
The Karl Fischer method is accurate, but the solid powder of the sample can’t be dissolved, so the direct injection method will contaminate the cuvette and electrode and make it impossible to find the sample. So, the Karl Fischer method of indirect injection is used, which means that the injection is done with a card heating furnace (also known as a card drying furnace).
As an extra part of the Karl Fischer moisture meter, the card heating furnace requires that the heated sample moisture enter the electrolytic cell of the Karl Fischer moisture meter without leaving any residue after it has evaporated. This puts more pressure on the heating components, pipeline components, and sealing components of the instrument.
Karl Fischer’s method of indirect sample injection is used, and the sample is put into a card heating furnace (also known as a card drying furnace). When the moisture in the sample evaporates when it is heated, it can go into the electrolytic cell of the Karl Fischer moisture meter without leaving anything behind that can be used to measure.
It can be used in the lithium-ion power battery industry for positive and negative materials as well as their raw materials, electrolyte, etc., such as lithium iron phosphate, lithium cobalt oxide, lithium manganate, lithium nickel oxide, ternary materials, negative membrane, graphite powder, etc. At the same time, it can be used to measure other solids that don’t dissolve.
How to lower the test error of the halogen moisture meter
The heating weight reduction method is used to test the halogen moisture meter. This method evaporates the sample’s moisture by heating it to a certain temperature, which lets the electronic balance figure out the percentage of moisture in the sample. The main thing that determines the result and how accurate it is is how accurate and stable the electronic balance is.
If there are other volatile solvents in the sample, they will also evaporate while the sample is heated. So, the part about losing weight doesn’t really show what weight is like. So, for now, it’s not a good idea to use the rapid moisture tester to figure out how wet the sample is. The error is bigger the more volatile the solvent is. For now, the error can be fixed by changing the temperature.
In this case, we suggest that users test the sample’s moisture level using either the Karl Fischer volumetric method or the coulometric method. Because Karl Fischer Reagent only reacts chemically with water, other solvents can’t change the amount of water in the test sample. It can be used to measure things like alcohol or benzene that evaporate quickly.
Of course, different methods can be used to test solid samples based on their properties. The volumetric method is easy to use if the sample is dissolved in methanol. If the solid sample is not dissolved in methanol, the coulometric method must be used, along with a solid gasifier.
How to solve the fault of the halogen moisture tester
A halogen moisture meter is a common kind in the laboratory. Some faults may be encountered when using a halogen moisture meter.
What are the causes and solutions to these faults?
- Power failure after startup. The fuse tube in the rear AC socket is broken, or the plug and socket of the power line are in poor contact. Replace the fuse plug and AC socket.
- The halogen tube is not bright, and the halogen tube wire is broken or broken. Replace the halogen tube.
- The weighing display is abnormal. Check whether there is foreign matter stuck between the weighing support and the through hole.
- The temperature display is abnormal. Check whether the temperature adjustment potentiometer and setting switch are loose.
General Faults and Solutions
- The display doesn’t light up at all.
The reasons may be that the moisture meter is not normally powered on; the moisture meter display switch is not turned on; instantaneous interference; or the fuse is damaged.
The solution is to try to connect the power supply; Switch on and off the moisture meter again or plug in the power cord again; adjust the fuse. If it burns out again, it must be sent to the maintenance unit.
- Zero ultra-light
The reason may be that the upper tray is not placed properly and the load is not light; the disc holder is not installed properly; the internal memory calibration number may be corrupted.
The solution is to reinstall the disc holder and touch any key to recalibrate the DSH fertilizer halogen moisture meter for weighing.
The reasons may be that there are heavy objects on the weighing plate when starting up; exceeding the maximum load; or the internal memory calibration number may be corrupted.
The solution is to remove the heavy objects from the weighing plate, reduce the load immediately, and Touch any key to recalibrate the moisture meter.
- The sample’s weight is excessive
The reason may be that the maximum load has been exceeded. The solution is to reduce the load immediately.
How to calibrate a halogen moisture meter?
Prepare the standard 20g weight and moisture meter, turn it on, press the calibration button in the lower right corner, and put the standard 20g weight in the middle of the sample tray when the instrument appears. (Remember not to cover the system during calibration to protect the heating lamp.) After calibration, the window on the instrument will show the number 20.
How to use a halogen moisture meter
- Startup: turn on the power supply and turn on the power switch at the rear of the instrument;
- Self-inspection: the weight display window displays, and the stable display window displays the initial value, which is generally room temperature (below 40 ℃);
- Preheating: start up and preheat for 30 minutes, and the data measured after preheating is true and valid;
- Setting out: open the heating barrel, put in the sample, close the heating barrel and wait for the weight display to stabilize for 20 seconds;
- Press the test key and wait for the instrument to heat itself.
- When the alarm sounds, press the display key once to display the discrimination time, and then press the display key again to display the final moisture value. Continuously press the display key to view other test parameters.
- After recording the data, press the clear key to clear the data, and then open the heating barrel. The next test can be carried out only after the temperature display returns to below 40 °C.