Moisture Analyser (Halogen / IR LOD Balance)
A balance with a built-in halogen or infrared heater. It dries a sample on the pan and calculates the loss on drying automatically, usually in a few minutes.
- Pharmaceutical
- Food
- Plastics
- Chemicals
- Agriculture
What is Moisture analyser?
A moisture analyser combines a precision balance and a heater in one unit. The sample is spread on a pan, the lid is closed and the heater warms the sample to a set temperature. The balance weighs the sample continuously as moisture evaporates.
The instrument stops when the mass stops changing (a switch-off criterion) or after a set time, and shows the result as % moisture (loss on drying). Results come in minutes rather than the hours needed in an oven.
In pharma it is widely used for in-process checks of granules during drying, blend moisture and quick checks of raw materials. Where a monograph specifies oven LOD, the moisture analyser method must be shown to give equivalent results.
Used for
- In-process moisture of granules during fluid-bed drying
- Quick LOD of excipients and blends
- Moisture of food and chemical products
- Screening before a full oven or KF test
How it works
- 01
Tare pan
Tare an empty aluminium pan on the balance.
- 02
Spread sample
Spread a set mass thinly and evenly.
- 03
Heat
Close the lid; the heater brings the sample to the set temperature.
- 04
Weigh continuously
The balance tracks mass loss as moisture leaves.
- 05
Switch-off
The test ends when the loss rate falls below the criterion.
- 06
Result
% LOD is calculated and printed.
Advantages
- Fast results (typically 3–15 minutes)
- Simple to operate
- Small sample size
- Automatic calculation and printout
Limitations
- Measures all volatiles, not only water
- Results depend on heating temperature, sample mass and spreading
- Needs method validation against the reference oven method
- Surface may scorch if the temperature is too high
2 calibration procedures
Keep every Moisture analyser in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.