Tool Calibration: Importance, Purposes, and Practices

You use tools to measure, test, or build things. But over time, tools can start to give the wrong results. That’s why you need to check them. In this guide, you’ll learn what tool calibration is, which tools to check, and how often to do it.

What is Calibration in Manufacturing?

Calibration is when you check if your tools or machines are measuring things correctly by comparing them to a standard that is already known to be accurate. If you make any changes, it’s a good idea to take another measurement afterward to make sure everything is accurate.

You can keep using a tool if it passes calibration. But if it fails, you’ll need to fix or replace it. After that, calibrate it again to be sure it works properly.

Once calibration is successful, make sure you write it down and add it to your records. Organizations like the FDA and ISO check these records during inspections.

Why is Tool Calibration Important?

Tool calibration keeps your work consistent and up to high-quality standards. Over time, tools can wear out, be used the wrong way, or be used too much. When this happens, their measurements can start to drift, so they will become less reliable and less accurate.

By calibrating your tools, you can:

• Spot problems early in the process
• Make your production more efficient
• Pass First Article Inspection (FAI) before going into full production
• Cut down on waste and save money on scrap

Which Tools Should Be Calibrated?

You use different tools to make products, and below we discuss some of the tools you should calibrate regularly:

Measuring Tools: Micrometers, height gauges, depth gauges, calipers, and dial indicators.

Станки с ЧПУ: CNC mills, routers, grinders, and lathes.

Testing Machines: Machines that test materials, like impact testers, tensile testers, and hardness testers.

Welding Equipment: Tools like welding gauges, plasma cutters, TIG, and MIG welders should be calibrated to control gas, current, and voltage for even and strong welds.

Laser Machines: Laser cutters and engravers need regular calibration so the laser stays focused and aligned.

Power and Hand Tools: Drills, saws, sanders, grinders, wrenches, pliers, screwdrivers, and other tools need calibration too. This helps avoid problems like poor torque or tool failure.

Tool Calibration Standards

Here are the most common standards you’ll need to follow:

ISO 9001

This is a worldwide standard for managing quality. It has a section (7.1.5) that talks about checking and measuring tools. Here are their tool calibration requirements:

• Calibrate your measuring tools at set times, using standards that can be traced back to national or international references.
• Make sure your tools are right for the job you’re using them for.
• Keep your tools in good condition.
• Protect your tools from being changed in a way that would mess up their calibration.

AS 9100

This one is for аэрокосмическая промышленность companies. It builds on ISO 9001 but has stricter rules. If you design, make, or supply products for space, aviation, or defense, you’ll likely need this. Your tools will be checked more closely than in other industries.

ISO 17025

This one is for calibration laboratories. It focuses on how the lab is run and how good their measurements are. Here’s what it checks:

• That your measurements can be traced back to recognized standards.
• That you understand and apply measurement uncertainty.
• That your team is well-trained and your lab environment is controlled.
• If you use a lab with this certification, you can trust that its calibrations are highly accurate.

ISO 13485

If you work with medical devices, this is the one for you. It applies if you make, install, or service medical equipment. This standard helps you meet strict healthcare rules, especially in places like the EU. Following this standard helps you stay compliant and safe.

MIL-STD-45662

This was one of the first calibration standards, made by the U.S. Department of Defense. Even though it was officially replaced in 1995, many companies still follow it. It helped build the foundation for today’s standards, like ISO 17025.

IATF 16949

This is for the automotive world. It’s based on ISO 9001, but it also includes rules just for car manufacturers and suppliers. This standard focuses on:

• Improving processes.
• Preventing defects.
• Reducing waste and differences in the supply chain.

Calibration Procedures for Various Purposes

You usually only need to calibrate when you need very accurate results or when the law requires it. That’s because calibration takes time and can cost money.

Calibrating Mechanical Devices

When you calibrate mechanical tools, you check things like weight, force, and torque. You might use it for devices like scales, load cells, torque wrenches, and balances.

To do this, you apply a known value, like a set weight or force, to your tool and then compare its reading to the known value. You’ll need different tools for each type of force or measurement you’re testing.

Calibrating Electrical Devices

Electrical calibration is used for devices that measure things like current, voltage, resistance, capacitance, and inductance. This includes tools like multimeters, oscilloscopes, and scope meters.

You compare your tool’s readings with a trusted and accurate device. The calibration equipment sends out known electrical values like voltage or current, and you check if your tool matches those values.

Calibrating Pressure Devices

You can calibrate both analog and digital pressure sensors. Analog sensors give you a continuous signal based on pressure. Digital ones turn on or off at certain pressure levels.

To calibrate pressure devices, you use a portable pump to create a known pressure. Then, you connect your pressure tool to the pump and compare the readings. Devices like pressure gauges, transducers, transmitters, and digital indicators are usually the ones you’ll calibrate.

Calibrating Temperature Devices

You use temperature calibration to check if your temperature sensors, like RTDs, thermocouples, or thermistors, are reading correctly.

There are two main ways to do this:

Physical simulation: You put your sensor in a controlled heat source, like a hot bath, and compare the sensor’s reading to the actual temperature.

Electronic simulation: You use a handheld device that sends an electric signal (like 0–10V or 4–20mA) that represents a certain temperature. You check if your system reads the correct temperature based on that signal.

Calibrating Humidity Devices

Humidity calibration is important in places like food, chemical, and pharmaceutical manufacturing. Moisture can damage electronics or cause corrosion if it’s not controlled.

You use a humidity generator to create air with a known level of humidity. Then, you compare your sensor’s reading with the generator’s value. If the readings match well, your sensor passes. If not, it fails.

How Often Should the Tools be Calibrated?

To keep your tools working their best, it’s a good idea to calibrate them at least once every 3 to 6 months. If you’re working in a high-production environment, you may need to calibrate more often.

But please note that there’s no one-size-fits-all schedule for tool calibration. How often you calibrate depends on things like the type of tool, how often you use it, and the environment you use it in.

ISO 9001 doesn’t tell you how often to calibrate tools. But it does say you need to keep a record. That record should show each tool, how often it’s supposed to be calibrated, and proof that it was done on time.

When deciding how often to calibrate your tools, think about:

Tool stability over time: If you check your tools regularly and write down the results, you’ll notice if the measurements start to drift or become less accurate.

Manufacturer recommendations: Many tool makers suggest calibrating after a certain number of uses. You can use this as a guide.

How important the measurements are: If you’re using the tool just for reference, and the measurements don’t affect the final product, you might not need to calibrate it as often.

Risks of inaccuracy: Some measurements matter more than others. If small errors won’t cause problems, you may not need to calibrate that tool as often.

Considerations and Practices for Tooling Calibration

Here are some simple tips to follow when calibrating your tools:

• Make sure you calibrate your tools regularly. When you stick to a schedule, you save money, improve your profits, and make better-quality products.
• Before you start calibrating tools, always follow safety rules. This protects you and your team from things like sharp edges or electrical problems.
• Always record what you do during calibration. Write down what standards you used and what results you got. This helps you prove that your measurements are accurate and match national or international standards.
• Even small changes in temperature can affect your tools. Heat can make them expand; cold can make them shrink. Things like humidity and vibrations can also throw off your results. Try to calibrate in a steady, controlled environment to keep things accurate.
• Look over your tools often. Check for dirt, damage, or signs of wear. If you use your tools in rough conditions, you may need to calibrate more often or even replace them.

DEK’s Custom Machining Services and Tool Calibration

DEK is here to help you with custom parts manufacturing. We offer CNC machining, 3D printing, and quick injection molding with high precision. We make sure our tools are carefully checked and adjusted so every machine works just right. This helps avoid mistakes and keeps your parts accurate

By following ISO 9001 standards, we give you results you can trust every time. Contact us and get a free quote.

Заключение

Calibrating your tools is a key part of the Inspection Test Report (ITR) process. It helps you keep quality control strong in manufacturing. When you regularly check and adjust your machines, equipment, and tools, you meet industry rules, make fewer defective products, and improve accuracy.

This also makes your customers happier. By calibrating tools and machines often, you make sure everything works well and your products stay high-quality before they leave the production line.

Вопросы и ответы

How to calibrate tools?

To calibrate tools, you compare their measurements to a known standard and adjust them if necessary. This process ensures the tool gives accurate results. It’s important to use reliable tools for calibration, such as micrometers or torque wrenches. A smart tool calibration system can amplify this by guiding the process, storing records, and reducing manual errors.

Why should you use tool calibration software?

Tool calibration software helps automate the process, reduce errors, and keep accurate records. It sends reminders when tools are due for calibration and stores all data in one place. Smart tool calibration systems can also track trends and performance over time.

What are the common challenges of tool calibration?

Many things can affect how accurate your calibration is. These include mistakes by the person doing the work, changes in temperature or humidity, and worn-out machines or tools. To get good results, make sure you follow the right steps, take care of your equipment regularly, and replace any parts that are old or damaged.