ANRITSU Capsule checkweigher



Capsule checkweigher


Industry-leading weighing performance enhances both production and research and development efforts.

Anritsu's capsule checkweighers have achieved the highest weighing precision in the industry* – ±0.5 mg. Here, we will describe the reasons why there is a demand for high precision weigh inspections and also provide an explanation of the newly developed balance used in ANRITSU capsule checkweighers.

* The highest weighing precision of ± 0.5 mg is based on ANRITSU survey results.


∴ Why there is a need in high precision mass inspections

   Next generation capsules

Currently most widely used general purpose capsules are "animal-derived" capsules that use gelatine as a raw material. However, for health and religious reasons, "plant-derived" capsules have been introduced.


Animal-derived capsules

Plant-derived capsules

Gelatine (cattle, pigs, fish, etc.) Hydroxypropyl methylcellulose (HPMC), pullulan (pulp, starch, etc.)
The manufacturing process has been established, enabling mass control within ±4 mg There are issues with the quality and variations in mass
General purpose capsules Addresses BSE, health and religious issues

There are likely to be variations in the mass of plant-derived capsules during production, therefore, highly precise mass control is required.

∴ ANRITSU weighting system has achieved the highest weighing accuracy in the industry – ±0.5 mg*

Best weighing solution for capsules containing active pharmaceutical ingredients.

   Even the slightest variances in active pharmaceutical ingredients can have a large impact on the efficacy of medicines.
Anritsu's force balance weighing technology provides the highest weight accuracy of +/-0.5 mg in the industry, meeting even the most stringent standards for capsules containing active pharmaceutical ingredients of high potency.

Force balance load cell

   For over 50 years, Anritsu has developed and manufactured their own load cells achieving the highest weighing accuracy in the industry.
Anritsu advanced force balance load cell achieves ultra-precise weighing, maintaining a compact size, which is perfect for pharmaceutical applications.


   In the force balance method, the load is balanced with a mechanical balance mechanism using a positioning sensor and an electromagnetic force. The mass is obtained from the size of the force coil current required for balancing. This allowed high precision of ±0.5 mg to be achieved, and as the mechanism does not require the use of oil or a spring, mechanical parts deteriorate slightly and there is no need for maintenance.

From the differential transformer method to the force balance method

   Principle of the force balance method that enabled high precision of ±0.5 mg to be achieved
The patented balance system of Anritsu with differential transformer method was used in regular devices using silicone oil as a damper and the displacement in the structural body using a spring was converted into an electric signal by the differential transformer to obtain the mass. Although it was highly precise (±2 mg) in 1997, due to degradation of oil and distortion of the balance (the mechanism) from prolonged use, regular maintenance was required.


Differential transformer

Force balance
Precision   ± 2mg  ± 0.5 mg
 Maintenance  Requires regular maintenance due to degradation of oil, etc.  Slight deterioration of mechanical parts, no need for regular maintenance.

∴ Resistant to extraneous vibration, provides consistent high precision

This method is more responsive than the differential transformer method, enabling highly precise mass measurements. Additionally, with a mechanism that makes fine adjustments to the balance state under a no-load condition, the impact of extraneous vibration was able to be reduced successfully.

This graph shows consistent precision even when the level of extraneous vibration (acceleration) is increased.

∴ Summary

Highest weighing precision in the industry - ±0.5 mg enhances both the production and mass check of pharmaceutical products.
Please use this device to develop and manufacture advanced pharmaceutical products.

∴ Stable and reliable feeding of semi-locked capsules

   The unique capsule handling technology from Anritsu prevents empty capsules from bouncing and provides stable feeding throughout the inspection process. Minimizing product vibration is of critical importance for high accuracy weighing. Accurate weighing of empty capsules can also improve the reliability of clinical trials and testing of new drugs.


Capsules in the magazine are fed by the shutter individually. The capsule holding unit minimizes any vibration generated from the impact of the drop from the magazine. The capsule is then transferred onto the weighting table.

Increase in highly active pharmaceutical preparations (such as anticancer drugs and immunosuppressants)

The number of highly active pharmaceutical preparations is increasing. Even a slight variance in the fill content can change their efficacy, and variability in the mass of the capsules themselves cannot be ignored.

Example - 10 mg capsule:

10mg-tablete 10mg-kapsula Longer elution time
Less active ingredient

As variability in the pre-filled (pre-lock) capsules results in variability in the elution time and amount of active ingredient, in addition to mass control of filled capsules, the mass of capsules prior to filling should to be strictly controlled for highly active pharmaceutical preparations. 

Every capsule in the system is monitored and tracked. Three rejection gates remove all defective products.


Now high precision weighing is easy.

∴ Complete line monitoring at a glance.

A large touch panel and user-friendly display offer simplified operation.

Complete line status is displayed on one single screen.

Large, intuitive touch screen graphical user interface provides fast assessment of production processes.

Displays histograms and trending information as well as underweight and overweight counts for each line, up to 10 lines at a time.


∴ Designed focusing on simple operation and safety.

Tool-free parts removal
Tool-less changeover of parts for capsules, which size is sizes from 000 to 5.

Preventing changeover part errors - an alarm will alert the operator if a wrong or mismatched part is installed on the system. 

Protection of weighcells - overload protection mechanism protects the load cell from accidental overload during magazine changeover.

Quick and easy sensitivity confirmation
It only takes 30 seconds for the built-in weight check to verify weigh cell sensitivity. Time, effort and risk of making an error are greatly reduced compared to traditional verification procedures. Each weigh cell can be individually calibrated with the built-in weights.

Data security
Anritsu capsule checkweighers comply with FDA 21 CFR Part 11 standard for electronic records data compliance.

Changeover of magazine
There are two built-in verification weights available, 500 and 2000 mg. The weight closest to the capsules in upper and lower limit weight values should be used for proper calibration.


Support for proper use of data in accordance with the functions of CFR 21 Part 11.

Ensurance of data integrity, as provided for in the FDA CFR 21 Part 11, using the data obtained from the network-connected machine.

  • Eligibility authentication (user management)
    All user access is managed centrally.
  • Audit trail
    The history of production-related operations and actions and results of operation checks are recorded and displayed as a list for easy and quick view.
  • Production process analysis
    Production process monitoring and Overall Equipment Effectiveness (OEE) can be viewed in real time.
  • Data for Quality
    Statistic data and individual data are recorded via Ethernet.