One thing you have to always keep in mind when using a dial indicator is the angle that it shapes to the surface must be 90°. In other words, the plunger and the surface being measured must be perpendicular. This angle is important in order to obtain correct measurement results and prevent cosine error.
Though measuring at a 90° angle, your indicator cannot be positioned underneath the object to be measured. In this case, gravity applies to the plunger and mislead the measurement reading.
In addition to using the dial indicator, you have to employ a rigid base. A base functions to hold the dial indicator during the measurement. This base is very important for stability and accuracy. Never ever use your hand to hold the dial meter for measurement because it won’t work.
You can use a magnetic base in this case. Insert the rod into the hole’s earplug and tighten it by screwing the screw. Put the base at an appropriate place in order to access the surface properly. The magnetic base will stick rigidly into the magnetic surface, and you can measure afterward.
Select the Contact Tip or Extension
Don’t forget to select your tip prior to the measurement. You can unscrew the contact tip from the plunger. There are several types of dial indicator contact tip shape: flat, rounded, pointed, and roller, just to name a few.
If needed, you can also unscrew the contact tip and replace it with an extension to add its length.
Zeroing the Dial Indicator
After you pick your tip, clean the surface from debris, and then direct the tip to the surface perpendicularly. Make sure the tip and the surface contact each other. Then, take a look at the reading. You have to slide the bezel to the right or left in order for the pointer to align with 0 number marking.
You can also slide the bezel after performing several measurements. Indicate the smallest reading, then slide the bezel in order the “0” marking aligns with the smallest reading.
After the “0” marking and pointer align each other, you need to tighten the bezel by screwing the top thumbscrew. Please don’t apply excessive screwing.
Take the Reading
You have to acknowledge the dial indicator spec before taking the dial indicator reading such as the resolution, travel range, and total divisions on the scale. Add the reading value of both the inner and outer scale to get the final reading.
Storing the Indicator
When storing the dial indicator, prefer the fitting storage so that no bump happens inside. Aside from that, you should put it in a dry place. Check the temperature and humidity, you could use a psychrometer or hygrometer so that it doesn’t corrode easily. If you have a digital dial indicator, removing the battery is important to do especially if you will not use it in a long term.