First you have to decide whether the probing method should be done by scanning or through discrete-point probing.

Scanning is preferable if the measurement involves:

• Form tolerancing
• Narrow tolerances
• (Probably) high form errors

Capturing individual points is recommended in particular for measuring size and position deviations that exhibit no narrow tolerances (esp. large workpieces). In general, the more probing points are captured, the more reliable and useful the measuring result will be.

You will find information on a useful number of probing points for a measurement in the measuring strategies of the ZEISS Cookbook. For more information please click here.

If you’re using tactile measuring devices, it’s essential to select the right stylus system. You have a number of options when it comes to selecting the right stylus tip:

• Ball-tip styli have the widest field of application as they exhibit the same probing behavior in every direction. Note the size of the stylus tip: the bigger it is, the bigger the mechanical filter will be. This means the profile of the workpiece will be smoothed. This is often desirable during form measurement. 
• Disk styli can be used in particular for measuring hard-to-reach areas. However, this usually results in strong filtering of the surface roughness.
• Cylindrical styli measure in 2D and are particularly suitable for flat workpieces such as thin sheets. 
• Star styli enable you to probe your workpiece from any direction and are thus frequently used for measuring side surfaces.

Find out more about selecting the ideal stylus system components here. 

It may seem like a chore for some people, but it’s vital that you keep your measuring machine and its accessories clean. It isn't just visible dirt that can cause incorrect measurement results - fine dust and oil residue can, too. That’s why cleanliness is essential.

You must ensure:

• Only use a lint-free cloth
• Only handle metal and glass components while wearing gloves
• Do not use any abrasive cleaning agents

Click here to find out more about how to properly care for your measuring machine.

During tactile measurement in particular, it’s very important to clamp the workpiece. First you must ensure that all elements being measured can be accessed by the styli. It’s also important that your workpiece is neither overtensioned nor too loose. Your workpiece will then still be able to “function” regardless of temperature fluctuations, i.e. react without becoming overtensioned.

Keep in mind:

• If the measurement of the workpiece is used for a function evaluation, the workpiece should be measured when installed. No forces should be exerted on the workpiece. Don’t forget: “Clamped as installed.” 
• However, if the measurement of the workpiece is used for production evaluation, make sure that the workpiece is measured in the original clamping, as during production. In this case: “Clamped as produced.”