Thickness Gauge: The Ultimate Guide

Thickness is an important parameter in tablet manufacturing process, a reason why you need a tablet gauge tester.

Therefore, quality control (QC) starts from consistently control tablet thickness.

But, how can you achieve this?

You must have a genuine and accurate thickness gauge tester.

And, in today’s guide, you’re going to learn how to find one.

Let’s dive right in.

What is a Thickness Gauge?

Thickness gauge or tester is an instrument that measures the thickness of tablets or capsules in millimeters.

Tablet thickness

Tablet thickness

You can measure the tablet thickness using either mechanical or digital instrument.

However, you can use a micrometer to measure the thickness of individual tablets.

Knowing the tablet thickness is essential for tablet packaging.

Very thick tablets have an effect on the packaging either in plastic containers or blisters.

You need to control the thickness within ± 5% variation of a standard value based on the size of the tablet.

The tablet thickness is the only dimensional feature associated with the process of compression.

Thickness tester machine

Thickness tester machine

This variable is constant within a batch or batch to batch only if:

  • Powder blend or tablet granulation is sufficiently constant size of particle and size distribution.
  • Punch tooling has of consistent length, and
  • You maintain the tablet pre in good working condition and clean.

Benefits of Thickness Gauge

  • Knowing the thickness of tablet or capsules you manufacture is critical in replicating tablets that have identical appearance.

Thickness gauge also helps you make sure that every production batch will be usable with chosen packaging components.

If you manufacture tablets which are thicker than the designated thickness, it may be difficult packing a given quantity in the volume of a specific size bottle.

  • Tablet gauge is as well crucial in counting tablets utilizing filling machine.

This is because certain filling machines applies the consistent thickness of the tablet as a mechanism of counting.

You measure the height of a column having a known amount of tablets.

You then accomplish the filling by continuously dropping columns of tablets having similar height into the bottles.

In case thickness differs throughout the batch the outcome will be variation of the count.

Other types of filling devices can malfunction due to variation in tablet thickness.

It is because tablets beyond designated thickness may lead to tablets wedging in previously modified depths of the counting slots.

As you can see, measuring thickness is an important tablet quality control process.

Implications of not Using Thickness Gauge during Tablets Production

Tablet tester equipment

Tablet tester equipment

  • Tablets of varying thickness result in packaging problems.
  • Tablets having greater thickness got lower internal stresses hence, reduced tendency to cap.
  • Adjustments in thickness often lead to faulty granulation deposition in the die or problem in the flow via the feeder.
  • Manufacturers place limits on the tablet thickness in order to make sure there is trouble-free packaging.
  • Tablets having inconsistent thickness have the potential of blocking the channels of counting equipment.
  • When you manufacture tablets that are thicker than normal, the packaging container turns out to be inadequate to carry the required quantity.

Key Parts of Thickness Gauge

Parts of a tablet tester gauge

Figure 4 Parts of a tablet tester gauge

01Crystal11120Z Main Gear ( Having 16Z Pinion )21Spindle
02Bezel1212Z Pinion22Guide Knock
03Pointer13120Z Idle Gear ( Having Hair Spring )23Coil Spring
04Outer Dial14Upper Metal ( fitted with Jewel )24Shock-Proof Rubber
05Hand15Wire Spring for Bezel25Anvil base
06Inner Dial16Set Screw for Upper Metal26Frame
07Base Metal ( fitted with Jewel )17*Claw27Cap
08Set Screw for Base Metal18Set Screw for Claw28Lever ( Having Lift Knock device )
09Guide Metal19Anvil29Set Screw for Lift
10Set Screw for Guide Metal 20Contact Point set30Back
31Set Screw for Back

Types of Thickness Gauge

There are many types of thickness gauge.

You can choose from mechanical to ultrasonic testers.

Hand held thickness tester

 Handheld thickness tester

· Mechanical Thickness Gauge

This is a simple, low-priced hand-held electronic thickness gauge that is specifically useful to the press operator.

It is convenient because the thickness tester is easy to use and absolutely dust resistant.

Mechanical tablet thickness gauge comes in handy in measuring the thickness of wall and peak of capsule and diameter of pill and tablet.

Mechanical thickness gauge

Mechanical thickness gauge

It is high-accuracy analytical equipment with the most precise, top-standard homemade centigrade meter.

· Digital Thickness Gauges

This are robust and compact data processors.

They offer a broad range of calculations for generating histograms, data displacement charts, and X-R control charts.

Digital thickness gauge

Mechanical thickness gauge

Normally, the thickness gauge has a special feature which enable you to use it in two modes.

Some have the feature of measuring thickness of tablet in either imperial or metric units with just a push of button with accuracy of 0.0005” or 0.01 mm.

Also, you can set some digital thickness gauge to zero at any given point.

You can use this instrument to measure tablet thickness in “direct measurement” mode where the machine displays the actual thickness value.

Also, you can do the measurement in “comparator” mode where the display shows a +/- variance from a preset norm.

It is possible to link the digital thickness gauge to a PC or Data Processor if you want.

· Digital Tablet Multi-parameter Tester

Tablet multi-parameter testers can measure up to five parameters like diameter/length, weight, width, hardness and thickness of almost all types of tablets.

Digital Tablet Testers are compliant with most international standards including EP and USP Pharmacopoeia.

Digital multi-parameter tester

Digital multi-parameter tester

This equipment blends both the precision and accuracy of a microprocessor modulated device.

The digital tablet multi-parameter tester has an ergonomic design that makes the insertion of tablet fast and convenient.

Its jaws automatically change for most shapes of tablet.

In addition, the equipment design is suitable for on-line testing in manufacturing areas.

Most digital tablet multi-parameter testers have several unique features that enables stress-free handling and measurement of tablet variables.

  • Tablet Positioning “flaps” to enable appropriate orientation of caplets, oblongs, or other peculiar shaped samples
  • Tablet Carousel which is helpful in transporting tablet to each of testing points
  • Tablet Transport track employing soft vibration to split up the tablets and place them into the tablet carousel
  • Feeder – Simply put your tablets or capsules in each container for automated testing of the batch

Special software which features several adjustable variables controls these digital tablet testers.

This allows for reliable testing of most shapes and types of tablets.

Normally, the instrument stores the testing procedure for every sample as a method.

Some of the information stored may include:

i. Descriptive product information

ii. Feeder speed of transport

iii. Tablet thickness of each batch

iv. Break detection

v. Movement of the flaps

Digital Tablet Multi-parameter testers immediately display file and present results as report including batch comparison features and statistical information.

You can download the data produced by the thickness gauge to a PC or Statistical Data Processor if you so wish.


  • Fully complies to most international regulations including the latest EP <2.9.8> and USP <1217>regulations
  • Tests diameter, hardness, weight, and thickness of tablets automatically
  • Fitted with a large an LCD and is simple to operate
  • Precise pacing of sample allows any tablet shape from 1.5 to 35mm diameter or length
  • Single and Multi batch feeders available
  • Unique flap feature to precisely position tablets thickness and diameter test
  • No change of tools needed to test different shapes of tablet
  • Stainless steel casing well appropriate for manufacturing environments

How a Thickness Gauge Works

Now, let’s have a quick overview on how thickness gauge tester works:

Tablet thickness tester

Tablet thickness tester

· Mechanical Thickness Gauge

Holding the thickness gauge in the right hand, press down the thumb lever using the right thumb to open the jaws of the gauge.

Using the left hand, insert the tablet between the jaws and then close the jaws by releasing the thumb lever.

Then read off the value measured from the thickness gauge display.

· Digital Thickness Gauge

  1. Make sure you have turned on the tablet thickness gauge. The LCD illuminates when it is on.

If not, press the ON/OFF button placed on the front of the gauge.

Choose measurement in millimeters or inches by pressing mm/in.

  1. Push down the lever found on top of the gauge which, will, in turn, make the plunger at the bottom to rise.

Position the tablet below the plunger and softly release the lever.

The tablet and the plunger are no in contact.

  1. The thickness value, in millimeters or inches, displays on LCD and LED of the thickness gauge.

If your instrument comes with a Report Center Printer, make sure you have turned it on and confirm if the LED is illuminating.

The printer print the thickness value as the gauge determines it.

Depress the lever above the thickness gauge once more to lift the plunger.

  1. Take out the tablet and then release the lever

It is not necessary to zero the gauge before placing the tablet on the tester.

This is because the tester calculates the difference between the starting and ending measurement.


How to test Thickness Gauge Accuracy

A vital decision on the general selection of an appropriate tablet thickness gauge is the degree of accuracy you need from the reading.

Within the variety of the types of thickness gauge available, they range from reasonably accurate to very accurate gauges.

You will realize this from the costs of the thickness gauges, the higher the accuracy level, the higher the price.

Tablet dimensions

Tablet dimensions

Several factors impact the accuracy in a specific application.

The factors comprise of appropriate calibration of the gauge, curvature, and surface texture of the tablet.

Therefore, you should consider all these factors when selecting a tablet thickness tester.

With correct calibration, you can make measurements to an accuracy of +/- 0.001″ or 0.01 mm, and in certain scenarios can 0.0001″ or 0.001 mm.

You can best determine the accuracy in a particular application by using reference standards of exactly known thickness.

In order to examine the accuracy of a specific thickness gauge, it is essential to have traceable tablet thickness standards.

Adjust the gauge to zero and then insert a tablet between the jaws.

Set the instrument to a known thickness standard at or close to the maximal thickness.

Measure the intermediate thickness standards and compare the readings to the actual thickness of the standard.

The difference between the value of the standard and the values of the reading are the errors.

These are best demonstrated as a percentage of the reading.

Why You Need to Calibrate a Thickness Gauge Before Testing

Calibration is the action of contrasting a reading on one instrument, with another instrument.

Of course, with an instrument already been calibrated and referenced to a recognized set of variables.

The equipment applied as reference should itself be traceable to an instrument that has gone calibration to the National standard.

Calibration determines the accuracy and quality of measurements registered by your thickness gauge.

There is an inclination for accuracy and results to drift specifically when employing particular technology or measuring specific parameters.

To boost confidence in the measured results, there is a continual need to maintain the calibration of the thickness gauge throughout its lifetime.

This ensures dependable, accurate and reproducible measurements.

You should calibrate the thickness gauge immediately after purchasing it and periodically after that.

This is important to make sure that it functions with the accuracy and precision the manufacturer designed it to deliver.

The gap between calibrations relies greatly on the criticality of the test and the workload of the tablet thickness gauge.



We recommend you perform calibration after every six month.

Calibration aims to reduce any uncertainty in measurement by guaranteeing the accuracy of the tablet thickness gauge.

Normally, calibration quantifies and moderates uncertainties or errors within processes of measurement to an acceptable level.

Disadvantages of not calibrating your thickness gauge

  • Safety procedure: Uncalibrated thickness gauge may lead to potential safety hazards to the consumer of your drugs.
  • Wastage:If you do not correctly calibrate your thickness gauge, it may result in possible wastage of raw materials and time taken in the operation. This eventually results in general increase in production costs.
  • Faulty or Questionable Quality: With improper calibration of the instrument, there are higher chances of people beginning to question the quality of your pharmaceutical products.

Calibration aids in maintaining the quality in manufacturing at various stages, which becomes compromised in case of any discrepancy.

  • Fines or litigations: Clients who have sustained damage may opt to return the pharmaceutical items for a full refund, which is still fine.

However, it would be a different case if they decide to go for litigation because of the damages.

Litigation could subject you to substantial costs in terms of restitution payments and reputation.

  • Increased downtime: The first sign of disrepair in your thickness gauge is poor quality of the produced tablets.

Regular calibration procedure recognizes warning signals early, enabling you to take the necessary action before the condition gets out of hand.

The calibration of your thickness gauge is the most primary maintenance requirement.

It is an established operation that every business entity utilizing instruments must carry out periodically.

You need to do the tablet thickness gauge calibration as per the requirements of the gadget.

Cleaning the Jaws

Apart from calibration, your thickness gauge needs little routine maintenance.

Nonetheless, you should clean the jaws constantly to remove tablet fragments and powder which could impact on the accuracy.



Here is the procedure of how to clean the jaws of tablet thickness gauge:

  1. Unfasten the thumbscrews and the washers which tighten each jaw. Be careful not to lose the washers.
  2. Lift the two jaws from the thickness gauge.
  3. Carefully cleanse the jaw plate using an appropriate solution.
  4. Use the brush included in the accessory kit to cleanse the jaws.
  5. Make sure the jaws are dry. Return them in their position and fasten each jaw using the washers and thumbscrews.

Factors to Consider when Buying a Thickness Gauge

When choosing a tablet thickness gauge for your intended application, you need to consider many factors before doing the purchase.

It is crucial to be aware beforehand of the functional capabilities of the instrument.

This helps to avoid any misconception between you and the manufacturer on the abilities of the equipment.

Technical specifications

Technical specifications

For that matter, let’s look at five main questions to assist you to make the right choice for your tablet thickness gauge requirements.

1) What is your budget?

The main thing that you should be conscious of is your budget.

Handheld tablet thickness gauges come in different prices.

Mostly, the cost vary from a few hundred dollars to above USD 4,000.

For that matter, choose a thickness gauge whose price is within your budget.

2) Consider technology

It is crucial to select a technology which will function well for your application.

However, you should know that there exist not a single technology that functions best for every application.

Your operating conditions may as well influence the technology you adopt for your application.

For instance, very hot environments can have an effect on the performance of the tablet thickness tester.

If the gauge cannot withstand dust or dirt that may as well be an essential factor to consider.

3) What is the accuracy I need currently or in the future?

When you are measuring the thickness of your tablets, you may be trying to comply with a particular variability specification.

Being aware of this specification is a perfect guide for ensuring that the technology you have settled on is suitable for your needs.

The resolutions on the tablet thickness will differ depending on the technology you are using.

Accuracy of the thickness gauge often relies on the average thickness of the tablet.

In addition, when testing a very thin tablet, the design of the gauge may differ versus a thick tablet.

4) Is my measurement dependable and repeatable?

It is very essential that the thickness gauge you utilize is dependable and repeatable.

A dependable measurement is one that you can quickly reproduce.

This implies that if two individuals take the measurements using the gauge, they get similar results.

However, it would be difficult to obtain a reliable measurement when measuring a very small tablet or capsule.

The design of a good thickness gauge should give the operator easy time in executing a good run technique.

5) Will the tablet thickness gauge be long-lasting under my working conditions?

The durability of your thickness gauge is an important consideration. Durability is a big consideration for many customers.

Many times, the surrounding can be dusty, experience big temperature changes, and have operatives who are less than fragile on the machine.

There need to be design features to deal with the situations on or off the production line.

You ought to also consider the type of battery, size, and weight.

Some thickness gauge are very minute and can fit in the pocket of your shirt and utilize the benefits of AA type alkaline batteries.

Others provide more than 24-hour battery life using the most current technology in Lithium Ion rechargeable batteries.

This benefit comes at the sacrifice of a bigger tablet thickness gauge.

In addition, you need to give careful consideration to the serviceability of the thickness gauge.

Its place of manufacture and the track record and customer service of the vendor.

6) Qualification of the Thickness Gauge

It is a requirement that any instrument used in the small laboratories, health care industries and pharmaceutical industries should always give valid and accurate data.

You establish the accuracy and integrity of a device through calibration, validation, and qualification.

This is very critical for all analytical laboratory equipment, and for every player in this sector, ho utilizes such instruments.

7) What is the importance of tablet thickness gauge qualification or validation?

Thickness gauge qualification is essential and necessary.

This is because it ensures that the device provides valid data and is compliant with the stipulations of medical device industries.

Your chosen manufacturer should always assist you in order to make the calibration easy.

Normally, they ensure this by giving out manuals that guide you on how to carry out the calibration.

Your thickness gauge might break down because of frequent use or wear thus needs repair.

After the repair, it will have to go through requalification to ensure it continues to function accurately.

8) Qualification Plan for your Tablet Thickness Gauge

Companies involved in the manufacturing of the thickness gauge has the obligation of preparing qualification plans for the equipment.

The plans will be applied as standard for the instrument throughout the world.

These plans define how the tablet thickness tester should run safely and constantly, as purposed.

The plans factors in the IQ OQ PQ Protocols detailed below as a mechanism of validating that your capsule thickness gauge complies with regulatory stipulations.

9) Design Qualifications (DQ)

Design qualifications are the definitions used by your manufacturer to describe the tablet thickness gauge.

The statements main aim is to manifest that the stipulations expressed in the User Requirements Specifications (URS) will be implemented satisfactorily prior to authorizing a new design.

The DQ describes the functional and operational specifications of the tablet thickness tester.

This protocol contains user requirements.

It should describe every requirement associated with quality, identity, strength, safety, and purity of the gauge.

The DQ needs to entail all the decisions made in choosing the manufacturer.

It will make sure your thickness gauge has all the needed functions and performance specifications to be successfully used for the planned purpose.

10) Installation Qualifications (IQ)

When you select a tablet thickness gauge for use at your facility, the specifications issued out by the manufacturer at the time of purchase are going to guide you on its usage.

IQ analyze whether your supplier satisfied all these specifications.

This is important as it makes you trust that the instrument will function as per the design.

For example, if it details that the thickness gauge has a specific power rating, the Installation Qualification makes sure that it is of that specific power rating.

11) Operational Qualification (OQ)

Operational qualification main intention is to challenge whether the tablet thickness gauge is working appropriately in accordance to its set specifications.

The gauge must operate as described in its specifications.

Remember, OQ is documented proof that your thickness gauge operates to satisfy design specifications.

The functions of the gauge undergo thorough scrutiny to make sure they comply with the instruments specifications by the manufacturer.

Guidelines emphasize the essence of the tablet thickness gauge qualification simulating real testing conditions, constituting worst-case scenarios.

You should repeat the tests and challenges an adequate number of times to guarantee reliable and meaningful outcomes.

There are no particular number of runs for your thickness gauge qualification.

However, multiple tests should be done to imitate real testing parameters and manifest consistency.

12) Performance qualification (PQ)

This step entails a physical analysis that tests the thickness gauge.

Its main purpose is to verify that the instrument actually functions consistently within the stipulated limits that have been put by the producer.

This is the protocol that certifies that you can actually begin utilizing the equipment.

The DQ IQ OQ PQ processes aid you spec out a tablet thickness gauge, buy it, install it if need be.

Then start on the task you purpose to undertake with a peace of mind.

Disadvantages of not doing Thickness Gauge Qualification

The quality of your pharmaceutical products will be questionable when you fail to qualify the tablet thickness gauge.

People will raise questions on the decisions reached to release the product.

The fact that you tested the produced tablets or capsules without assured confidence will raise questions.

Handhold thickness tester

Handhold thickness tester

Consumers will not be sure whether they are substandard or maybe even adulterated.

A pharmaceutical product perceived as adulterated will lead to a recall and a great cost to you in terms of lost revenue.

It will as well lead to regulatory audits, citations, warning letters, observations, and possibly even a consent decree with probable criminal prosecutions.

All of these can come at a huge cost to you the producer in the tune of millions of dollars.

Registered costs have been as high as USD 500 million, with lost sales to the tune of USD 250 million.

These leave out the millions of dollars that you may be forced to pay out in civil lawsuits due to injury or harm to the consumers.

Civil litigation costs can be more than USD 10 million.

Analytical instruments, like tablet thickness gauge, can give a high level of trust in the integrity and quality of your manufactured items through scientific data.

You can only achieve that trust through proper thickness gauge qualification.

Failure to qualify your thickness tester may result in consumers assuming your products as adulterated and this may cost you millions of dollars.

Applications of Thickness Gauge

As we have mentioned throughout the article, the main use of a tablet thickness gauge is to measure the thickness of tablets or capsules of varying shapes and size.

Measuring thickness

Measuring thickness

This simple gadget is useful in measuring the thickness of oblong, cylindrical, round, and any other shape of tablets and capsules.


Tablet thickness is a crucial scientific data about the tablets and capsules you manufacture.

This data guarantees confidence that you have produced a quality product which is suitable and safe for public consumption.

Therefore, as manufacturers, it is your obligation to make sure you strictly control your tablet thickness gauge.

Qualification of analytical instruments is a must procedure, just as it is with manufacturing equipment.

You have to manifest consistency, reliability, and repeatability to guarantee the quality of pharmaceuticals you produce.

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