How to use a telescopic gauge?

Step 1 – Select gauge size

Select the correct size of telescopic gauge for the size of bore you wish to measure.

Step 2 – Lock telescopic rods

Using your finger and thumb on your dominant hand press the two telescopic rods into their casing. Whilst still holding the telescopic rods in position use your non-dominant hand to turn the locking screw in a clockwise direction to hold them in position.

Step 3 – Place gauge in bore

Place the top of the telescopic gauge inside the bore at the exact position you wish to measure. Then slowly twist the locking screw anticlockwise until the telescopic rods come out of their casing. Continue twisting the locking screw until the ends of the telescopic rod touch the sides of the bore.

Step 4 – Self centring

Next you will need to rock the gauge with the handle backwards and forwards slightly to make sure the gauge is perfectly aligned with the diameter you wish to measure.

Step 5 – Lock telescopic rods

Twist the locking screw clockwise until the telescopic rods are held firmly in place, and remove the tool from the hole.

Step 6 – Measure telescopic rods

Finally you will need to measure the ends of the telescopic rods with either a micrometre or a vernier calliper for an accurate measurement of the diameter.