Friability tester · Calibration procedure
Rotation speed & count
Checks the drum turns at 25 ± 1 rpm and stops after the set number of revolutions.
PURPOSE
Why this is checked
Friability is a fixed amount of tumbling. If the speed or the count is wrong, tablets receive more or less stress than intended.
Frequency
Typically every 6 months, as defined in your calibration SOP.
Learn how the Friability tester worksYOU WILL NEED
Standards & tools
- Calibrated stopwatch
- Optional calibrated tachometer
BEFORE YOU START
Prerequisites
- Drum clean and fitted
- Counter set to 100 revolutions
PROCEDURE
Step by step
- 1Mark a reference point on the drum.
- 2Start the drum with the counter set to 100 and the stopwatch running.
- 3Count the revolutions by watching the mark and stop the stopwatch when the drum stops.
- 4Calculate rpm = revolutions ÷ time in minutes.
- 5Repeat three times (and for each drum on dual-drum models).
RECORD
Example observation table
| Trial | Set revolutions | Counted revolutions | Time (s) | Speed (rpm) |
|---|---|---|---|---|
| 1 | 100 | 100 | 240.5 | 24.95 |
| 2 | 100 | 100 | 239.6 | 25.04 |
| 3 | 100 | 100 | 240.2 | 24.98 |
CALCULATION
How to calculate the result
Speed (rpm) = Revolutions ÷ (Time in seconds ÷ 60)
- Trial 1: 100 revolutions in 240.5 s
- Speed = 100 ÷ (240.5 ÷ 60) = 100 ÷ 4.008 = 24.95 rpm (within 25 ± 1 rpm)
ACCEPTANCE CRITERIA
Pass if
- Speed 25 ± 1 rpm.
- Counted revolutions equal to the set number (e.g. 100).
IF IT FAILS
What to do
- Label out of calibration
- Service the motor or counter
- Recalibrate before use
In LimsPulse · Calibration Management
LimsPulse schedules this calibration, records the result against limits, and blocks the instrument everywhere if it fails or goes overdue.