How much sample should I use in a moisture analyzer?

Most methods use 2 to 10 g spread in a thin, even layer, but the right mass depends on the balance readability and the moisture level. As a working rule, the sample mass should be large enough that the measured mass loss is at least a hundred times the readability, so a 1 mg readability instrument needs a sample that loses more than about 100 mg. Too little sample gives poor repeatability; too much slows drying and can char the surface.

Moisture Analyzers Singapore — Halogen and Infrared Loss-on-Drying

Q: What is the difference between a moisture analyzer and Karl Fischer titration?

A moisture analyzer measures loss on drying: it heats the sample and weighs what disappears, so it reports all volatile matter, not water alone. Karl Fischer titration is water-specific and can measure down to parts per million, which matters for solvents, oils and low-moisture polymers. Loss on drying is faster and cheaper and is the routine method for food, feed, plastics and many pharmaceutical raw materials, but it must be validated against a reference method for each product.

Q: How often should a moisture analyzer be calibrated?

Temperature and weighing accuracy should be checked at least annually, and many quality systems require quarterly or six-monthly checks. Weighing can be verified with OIML or ASTM calibration weights, while heating performance is checked with an external temperature probe or a certified reference material. Daily or per-batch checks with a stable in-house reference sample catch drift far earlier than an annual service visit.

Q: Does JWRESEARCH supply moisture analyzers in Singapore?

Yes. JWRESEARCH supplies halogen and infrared moisture analyzers with 50 g to 200 g capacity and 0.1 mg to 1 mg readability, together with aluminium sample pans, glass fibre filters, calibration weights, temperature probes and spare lamps. We support method development, installation and local delivery across Singapore.

Published: {{NEW_ARTICLE_DATE}} | By JWRESEARCH | Category: Laboratory Equipment

Moisture changes the price of a commodity, the shelf life of a food and the strength of a polymer, yet it is often measured carelessly. A moisture analyzer gives an answer in minutes, without an oven, desiccator or overnight wait — provided the method is sound.

JW RESEARCH SUPPLY supplies halogen and infrared moisture analyzers, pans and accessories to food, pharmaceutical, polymer and chemical laboratories in Singapore. This guide covers how loss-on-drying works, what the specifications mean, and how to set up and validate a method.

How a Moisture Analyzer Works

A moisture analyzer is a precision balance with a heater above the pan. The sample is weighed, dried, and weighed again; moisture is calculated from the mass loss as a percentage of the initial mass. Modern instruments record mass continuously, plot a drying curve and stop when the weight is stable.

That simplicity is the limitation. Loss on drying measures everything volatile — water, solvents, fatty acids, decomposition products — so the result is only "moisture" if the method matches a water-specific reference such as Karl Fischer titration or a validated oven method.

Halogen, Infrared and Microwave Heating

Halogen lamps reach setpoint in seconds, shortening the cycle for high-throughput QC. Ceramic infrared heaters respond more slowly but spread heat evenly, which suits pasty and inhomogeneous samples. Microwave analysers are faster still, mainly for grain and bulk food, but method transfer is harder.

Typical Specifications

Class	Capacity	Readability	Heating	Temperature Range	Typical Samples
Entry / routine	50 g	1 mg	Halogen	40 – 160 °C	Feed, grain, incoming raw materials
Standard QC	100 g	1 mg	Halogen or ceramic IR	40 – 200 °C	Food powders, excipients, plastics
Precision	100 g	0.1 mg	Halogen	40 – 200 °C	Low-moisture polymers, fine chemicals
High capacity	200 g	1 mg	Halogen	40 – 200 °C	Bulk powders, slurries, fibrous material
Microwave	100 – 200 g	1 mg	Microwave	Programme dependent	Grain, bulk food, high-throughput screening

Readability applies to the balance, not the moisture result. Resolution is readability divided by sample mass: 0.1 mg on 2 g resolves 0.005%, while 1 mg on the same sample resolves 0.05%. Buy readability only when sample mass and specification justify it.

Setting the Method

Sample mass, preparation, temperature and endpoint determine repeatability. The table gives starting points for common matrices — a basis for development, not validated methods.

Sample Type	Typical Mass	Starting Temperature	Endpoint	Approx. Cycle
Food powders, flour, starch	3 – 5 g	105 – 130 °C	Auto, 1 mg / 30 s	8 – 15 min
Pharmaceutical excipients	2 – 5 g	105 °C	Auto, 0.5 mg / 30 s	10 – 20 min
Polymers and masterbatch	5 – 10 g	140 – 180 °C	Auto, 1 mg / 60 s	10 – 25 min
Sugars and syrups	2 – 3 g	70 – 90 °C	Auto, slow ramp	15 – 30 min
Pasty or liquid samples	2 – 3 g on glass fibre	80 – 105 °C	Auto, 1 mg / 30 s	10 – 20 min

Grind and mix so the portion represents the batch; a 3 g scoop of coarse powder can differ from the bulk by several percent. Spread it thinly — a thick mound dries from the top down. For liquids and pastes, use a glass fibre filter to prevent spattering.

Prefer an auto endpoint based on mass-loss rate over a fixed time. Soft or stepped profiles protect sugars, fats and thermolabile actives from charring.

Living With Singapore Humidity

Singapore humidity often exceeds 75% RH, and hygroscopic powders pick up water while being weighed. Keep samples sealed, scoop quickly, and warm chilled samples in a sealed bag before opening.

Validation and Routine Checks

Validate each product method against a reference — forced-air oven at 105 °C, vacuum oven or Karl Fischer — at three or more levels, and document the correlation. A method that reads two points high but repeats perfectly is still wrong.

For routine control, check weighing with calibration weights and heating with an external probe. Run a stable reference sample on a control chart, and clean the pan and sensor after every batch — residue becomes part of the next sample's mass.

Do not use moisture analyzers for flammable solvents, toxic materials or violently decomposing samples. Work in a fume hood and never override the over-temperature cut-out.

Frequently Asked Questions

What is the difference between a moisture analyzer and Karl Fischer titration?
Loss on drying measures all volatiles; Karl Fischer measures water specifically down to parts per million. Use loss on drying for routine food, feed and plastics; Karl Fischer for solvents, oils and low-moisture polymers.

How much sample should I use?
Usually 2 to 10 g in a thin layer, with a mass loss at least a hundred times the readability — a 1 mg instrument needs roughly 100 mg of loss.

How often should a moisture analyzer be calibrated?
At least annually for temperature and weighing, more often if your quality system requires it. Reference-sample checks catch drift far earlier.

Does JWRESEARCH supply moisture analyzers in Singapore?
Yes — halogen and infrared models from 50 g to 200 g capacity, with pans, filters, calibration weights, probes and lamps, delivered locally.

Ordering Checklist

Typical sample type and expected moisture range
Sample mass your method needs, and the resulting readability requirement
Heating technology preferred: halogen, ceramic infrared or microwave
Temperature range and whether stepped or soft profiles are needed
Endpoint modes and data output required by your quality system
Consumables: aluminium pans, glass fibre filters, spare lamps
Calibration weights, temperature probe and service interval

Tell us what you measure and the specification, and we will propose an instrument, starting method and consumables, delivered in Singapore.

Contact JWRESEARCH

JW RESEARCH SUPPLY — laboratory equipment and consumables, Singapore.
Telephone / WhatsApp: +65 8039 3660
Email: SINGAPORE@JWSHY.COM
Website: www.jwresearch.cn