From automotive and medical device manufacturing to children’s toys and more, batteries play an important role in nearly every industry. And with so many industries and individuals reliant upon the power that these batteries supply, it is important for manufacturers to keep a tight grip on quality throughout the production process.
Moisture is Problematic in Battery Production
Keeping battery materials within a controlled moisture range is essential to the functionality of the end product. Too much moisture in a battery causes corrosion and short circuiting. It also decreases performance, accelerates material degradation and significantly reduces life expectancy of the final product.
Many battery manufacturers utilize dry rooms to reduce the likelihood of moisture contamination during production. However, while dry rooms are very effective, even the most sophisticated dry room cannot completely prevent battery components from coming into contact with moisture. In an industry where even trace amounts of moisture can mean the difference between a well-made part and scrap, it is imperative to test raw materials before they are made into batteries.
Karl Fischer is the Traditional Method of Moisture Analysis
There are many ways to test the moisture content of battery materials. However, for the purposes of this experiment, we will be focusing on moisture specific methods that are suitable for trace water analysis.
Perhaps the most widely used method of moisture analysis for battery components is Karl Fischer titration. Although it is capable of producing moisture specific results that are both accurate and precise, KF titration is difficult to use unless operated by someone with the proper training. A specially trained analyst also needs to be on hand to repair or perform troubleshooting on the KF should something go wrong. Karl Fischer also requires expensive chemical reagents that must be routinely disposed of and replaced, adding to the high cost of ownership of a KF titrator.
Computrac Offers a Modern, Chemical Free Alternative
An alternative to Karl Fischer titration that is gaining in popularity is a moisture analyzer that uses a relative humidity (RH) sensor to measure the water specific moisture content. The Computrac® Vapor Pro® XL is an example of such an instrument. The nature of the RH method coupled with its lack of hazardous chemical reagents and expensive glassware means that it is more durable and cost effective than Karl Fischer. It is also easier to use for those who lack the technical training required for Karl Fischer.
The Computrac® Vapor Pro® XL
The Computrac® Vapor Pro® XL in particular boasts a comparable lower detection limit to that of Karl Fischer (10 ppm) and has an upgraded heater that allows for improved control over testing temperatures. It is far easier to use – with an integrated touchscreen, full on-screen keyboard and intuitive menu system – and features a redesigned bottle transport that allows users to test samples in multiple sizes of sample vials.
Both Methods were Tested Using Several Materials
In order to prove the RH sensor moisture analyzer’s equivalence to Karl Fischer, six battery materials and/or components were tested. All were analyzed using the RH method and coulometric KF titration with an oven attachment.
The RH sensor moisture analyzer used for this experiment consists of a relative humidity sensor with two plates that have a constant dielectric difference between them. When moisture travels between the plates, it changes the capacitance. That change is then used to calculate the amount of moisture present in the sample.
The RH Method is More Precise and Just as Accurate as Karl Fischer
As you can see from the graph above and the chart below, the RH sensor method (blue), produces results that correlate well with Karl Fischer (orange) over a wide range of moisture contents. Tests on the Computrac Vapor Pro instrument have tighter standard deviations and lower coefficients of variation, making the Vapor Pro more precise than Karl Fischer without sacrificing accuracy. It is also far easier to use for non-technical staff, improving the repeatability of results between tests performed by different individuals. The Computrac Vapor Pro more cost effective due to its lack of hazardous chemical reagents and expensive glassware.
The RH Method is a Viable Alternative to Karl Fischer Titration
Whether you’re manufacturing batteries for use in the automotive or medical device industries, for use in children’s toys or simply producing AAs for consumers, accurate monitoring and control of moisture is critical to the quality control process. Even a small amount of water can significantly decrease performance, efficiency and life expectancy of the battery. While the accuracy and precision of Karl Fischer titration when performed by a trained professional cannot be disputed, the Computrac Vapor Pro has proven to be just as accurate and, in some cases, more precise while being significantly easier to operate.
If you have any questions or would like to learn more about the Computrac Vapor Pro XL, contact us online, check out our page about moisture and solids analysis for batteries, or give us a call at (800) 528-7411.