Defective, leaking capsules are becoming a quality issue during filling

Master the simple Go/No-Go gauge tool to check the quality of any filled capsule

Go/no go gauge for capsules


Locking a filled capsule completes the filling process, but the quality detail does not end there.  

In a filling operation, a two-piece capsule must be properly locked to ensure the cap and the body never fall apart. At the same time, the capsule must not be overclosed as to cause dents or tears in the capsule body due to pressure. An 'unlock' or 'overclose' during the filling process is revealed in the final length of the capsule, and this detail is checked for in every good quality product.  

The capsule length gauge, also called the Go/No-Go gauge, is a tool to verify that a capsule has been filled and locked properly by the filling machine. This article explains the design, application, and use of the go/no-go gauge tool that should be included in your capsule quality control toolset. 

The Go/No-Go gauge 

The Go/No-go gauges are a popular tool in the capsule manufacturing sector, where they are used for quick assessment of dimensions of machine parts or finished products for allowed tolerances. Well-known examples of the go/no-go gauges are the plug gauge, pin gauge and the snap gauge. 

One peculiarity of the Go/No-no gauges is that they are measurement tools which do not report an actual measurement value, they rather reflect states – i.e. within tolerance or out of tolerance, or; Go or No-go. In other words, the gauge parts are built to fixed dimensions which the dimensions of the measured items must fit to pass (Go) or, exceed or short to fail (No-go). 

The working principle of all Go/No-go gauges is such that the article to be measured passes the Go test and fails the No-go test or vice versa. The main advantage of this inspection device is its ease of use and the rapid assessment it delivers. 

The capsule length gauge, as a type of go/no gauge, verifies proper locking of a filled capsule via its final length. It intuitively reveals substantial information about the finished capsule quality and shelf stability via a simple check. Compared to the micrometer screw gauge and similar quantitative manual gauges, the go/no-go gauge is much quicker, simpler to use, and requires little to no specialized operational or result interpretation skills.   

How the modern capsule Go/No-Go Gauge work 

The capsule go/no-gauge is calibrated based on the locked lengths of the various capsule sizes available in the market. You may check the overall locked length for different sizes of commercial capsules in the image below. 

Empty capsules sizes

Modern gauges, such as the Capsuline capsule length gauge, have the dimensions of all commercial capsule sizes fashioned out on just one gauge. This offers a cost-effective option than using multiple gauges to capture the different capsule types.  

Shaped in the form of a giant key, the multi-capsule length gauge has pockets and ridges on both sides and at the tip that are used for measurement. Each pocket serves as a scale for different capsule-size locked length, with ridges to differentiate the Go and No-Go dimensions. For example, within each pocket of the Capsuline capsule length gauge, the "Go" region at the upper section has a slightly larger width than the "No-Go" region at the bottom. 

Measurements are taken by putting a capsule against its corresponding pocket on the gauge to determine the length. The Capsuline capsule length gauge, uses a checkmark "✔️" to indicate the Go tolerance range, and the rejection sign "❌" to the denote the No-Go dimensions.  

The 'lock' statuses of a filled capsule that can be revealed by the gauge include: 

How the modern capsule Go/No-Go Gauge work

  • Properly closed: when the measured capsule fits comfortably in the Go region of its pocket and is too big to pass into the 'No-Go' pocket below it. 
  • Not locked: when the capsule is too big to fit in the Go region of its pocket. That counts as a No-Go reading. 
  • Over-closed: when the capsule is too small for the Go region and is accommodated only in the No-Go region of the pocket. 

Getting the best capsule length gauge  

The capsule Go/No-go gauge is preferred in quality control operations because of its quick and simple use. However, it is prone to wear-and-tear which may affect its accuracy, especially if made with unstable and degradable materials. Thus, it is important to craft the gauge with appropriate material to assure its durability and functionality for a longer period. 

A good quality Go/No-go gauge is made with materials that: 

  • Have optimal hardness and strength, but not too heavy. The gauge should be lightweight. 
  • Are resistant to wear-and-tear and corrosion, and preferably have polished surfaces.  
  • Have high thermal stability.  

The Capsuline Go/No-Go gauge is made of stainless steel. It is intricately designed to give fast and accurate measurement for nine different capsule sizes, with just one gauge The gauge is strong, polished, highly durable, lightweight, and resistant to moisture and rust. 

Our gauge is a simple and inexpensive tool to validate the performance of your filling machine and the quality of the filled capsules. It is a must-have for the filling plant operators at your manufacturing facility. 

If you would like to buy the Capsuline capsule length gauge, you can order on our website now


Cracks and dents may cause leaky capsules when the filling machine locks the capsules too tightly. Fill ingredients may also be lost when machine failure turns out poorly capped capsules. To prevent any of these unwanted scenarios, the QC must have these checked before the products are packaged. Using the Go/No-go capsule length gauge might be your absolutely cheapest way to do that.

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Capsule Length Gauge by Capsuline
Capsule Length Gauge by Capsuline

Capsule Length Gauge by Capsuline

Regular price$49.99
Shipping calculated at checkout.

Capsuline's Length Gauge is a tool used to verify that filled capsules are being closed to the correct length by the filling machine.

  • Made of Aluminum