Welcome to Issue #68 


Welcome to the May edition of "Dynamic Sensors & Calibration Tips."  Last week, we observed World Metrology Day, signed into effect by seventeen representatives on May 20, 1875, at the Meter Convention. This set the framework for global collaboration in the science of measurement and its industrial, commercial and societal applications. The Modal Shop and the PCB Group of companies are proud to continue developing and supporting the metrology framework of dynamic sensing critical science, technology and commerce of virtually every field touched by mechanical design.

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Tip of the Month: 

Calibrating Proximity Probes

When mounting a proximity probe, one must know the specified case thread, not the tip diameter. The tip diameter is the number specified in the model number.


Common case sizes are 1/4 inch, 3/8 inch, M8 and M10.

Technical Exchanges
June 4-6, 2013  
June 25, 2013   
July 14-18, 2013  
Dynamic Sensors & Calibration Seminar - Nashville, TN
 July 19, 2013
Quick Links
ISO TC 108 - Mechanical vibration, shock and condition monitoring
ISO TC 108/SC 3 - Use and calibration of vibration and shock measuring instruments
ISO TC 108/SC 6 - Vibration and shock generating systems
SAVE (Formerly SAVIAC)
Previous Newsletters
NIST to Reaffirm Vibration Calibration; Low Frequency Calibration Needs Support Standard ISO 8041:2005
Does a Manufacturer's Nominal Spec Matter?; Technology Fundamentals of Microphone Types
Select Newsletter Articles 
by Topic
PCB Group Companies

How Low Can Your Digital Volt Meter (DVM) Go?

Recently, we have had a few follow-on reader digital volt meter questions regarding low frequency vibration calibration. The questions mostly stem from the misconception that traditional digital volt meters cannot measure accurately below 20 Hz.  While this is true for inexpensive, entry-level digital volt meters, there are a number of other models which will work quite well in the low frequency range.

Non-Contact Displacement Sensor Calibration

Mounted Proximity Probe Non-contact displacement sensors, also known as proximity probes, eddy current probes or simply displacement probes, can be checked for accuracy, linearity and frequency response.  With a proximity probe adaptor fixture, some portable vibration calibrators can be adapted for a quick and easy calibration.  The following excerpt details the procedure for performing linearity and frequency response checks on a non-contact displacement sensor.   

Click to read full article
Blast From The Past: 
Accelerometer Application Focus 
On Seismic Sensors

As you may remember from your studies (or maybe seismic accelerometer you read the first newsletter in this series)ideal sensors provide straight line performance.  That is to say, they treat amplitudes proportionally (straight line linearity), frequencies of interest the same (flat amplitude frequency response), and do not appreciably delay the signal (flat phase frequency response).  Hence, the frequency response output plot from an accelerometer and on a calibration system should be a flat line. In the real world, however, things are not perfect...  


  Click to read full article



Thanks for joining us for another issue of "Dynamic Sensors & Calibration Tips." As always, please, speak up and let us know what you like. We appreciate all feedback: positive, critical or otherwise. Take care!




Mike Lally signature
Michael J. Lally
The Modal Shop
A PCB Group Company