Moisture Analyzer ASTM Standards and Which Method Applies
By Lim Xu, Export Manager
A practical map of ASTM moisture and loss-on-drying methods, including D6980, D6869 and E1868, with a checklist for choosing an SOP.
A moisture analyzer ASTM standard is not one universal document. ASTM methods define different measurands and materials: one may determine mass lost on heating, while another measures water through a chemical reaction. Start with the material and the decision your lab needs to make, then check the scope of the current method before choosing equipment.
Which ASTM methods are relevant?
| Method | Published topic | First question for the lab |
|---|---|---|
| ASTM D6980 | Moisture in most plastics by loss in weight | Does the plastic and required range fit the method scope? |
| ASTM D6869 | Water in plastics by Karl Fischer reaction | Is a water-specific result required? |
| ASTM E1868 | Loss on drying by thermogravimetry | Does the material and procedure fit the intended measurement? |
These are method descriptions, not a list of standards that any KHT model automatically meets. A product's heating source alone does not establish compliance with a test method.
ASTM D6980 and plastics
ASTM D6980 covers quantitative moisture determination in most plastics using loss-in-weight technology. The ASTM scope identifies the material and measurement principle; it does not mean every halogen balance is configured for the method. Check the apparatus, sample preparation, operating procedure and reporting requirements in the current standard before claiming a result under D6980.
The term “moisture” in a loss-in-weight result needs care where other volatile constituents can leave during heating. If the acceptance decision requires a water-specific result, compare the candidate method with a water-specific alternative.
Questions about a model or a test? Email Amy Zhao, Export Manager, at info@halogenmoistureanalyzer.com.
ASTM D6869 and Karl Fischer
ASTM D6869 uses the Karl Fischer reaction to determine water in plastics. It is a different measurement principle from a heated balance. The two results should not be substituted merely because they are both reported as percentages.
ASTM notes that some plastic constituents may interfere with the Karl Fischer reaction. Check the material and method scope in either case. ISO 15512 also addresses water content in plastic powders, granules and finished articles through several methods; it is another standard to inspect when the specification names it.
Other loss-on-drying standards
ASTM E1868 is a loss-on-drying method by thermogravimetry. Its title is useful for distinguishing a mass-loss measurement from a water-specific one, but it does not turn a general moisture analyzer into a compliant E1868 apparatus. The required instrument, program and reporting must be checked in the standard itself.
The lab should also distinguish a standard test method from an internal screening procedure. Screening can be valuable for monitoring a process trend, while a contract or specification may require a named reference procedure for acceptance.
How to cite a standard in your SOP
Record the standard identifier and edition used by the lab, the material covered, the specimen preparation, the instrument configuration and the required result fields. Write the selected method into the SOP, then train operators to use those settings consistently.
If a proposed analyzer program differs from the specified method, document a comparison on the actual material and decision range. Do not label the new program “ASTM D6980” solely because it uses heating and weighing. Ask KHT to confirm the apparatus and options for a specific method before ordering. The halogen moisture analyzer product page describes the available heating and weighing functions, not a blanket ASTM method approval.
Further reading and methods
Frequently asked questions
Is ASTM D6980 a food moisture method?
No. ASTM describes D6980 as a method for most plastics. Food products need a method appropriate to their own material and specification.
Can Karl Fischer and loss on drying give different results?
Yes. They measure different things: Karl Fischer responds to water through a chemical reaction, while loss on drying records mass lost under heating conditions. Interpret each result within its method.
Discuss the required method with KHT
We sell direct from our factory, so you work directly with our factory team.
Questions about a model or a test? Email Amy Zhao, Export Manager, at info@halogenmoistureanalyzer.com. Send the material, standard and report requirements through Get a Quote so we can check a suitable configuration.
