VOGEL Crankshaft Testing Instrument is used for measuring deflection of Crankshafts in the marine and engine building industry. Measures 60mm-500mm. Comes with 7 attachments 

• Precise Measurement Dial Indicator measures up to 0.01mm
• Modular attachments allow for different length measurements
• Highly accurate dial gauge with larger display
• measuring pins protected in foam inlay to retain accuracy
  

How to use a Crankshaft gauge

Step #1: Choose correct attachments to dial indicator in set based on gap and tolerance requirements of your shafts
Step #2: Secure tips firmly to workpiece
Step #3: Zero the dial
Step #4: gently rotate workpiece to see amount of deflection and adjust the shaft accordingly to give a good alignment.