Guide
How do I specify a shaker?
An electrodynamic shaker is a very large loudspeaker driving a table. A coil in a magnetic field pushes the table up and down, following whatever waveform the controller demands: a swept sine, a random spectrum, a recorded road profile, or a shock pulse.
Also called: shaker, shaker table, electrodynamic shaker, ED shaker, shake table, vibration table, vibe test, HALT HASS, shock machine, drop tester, bump test, random vibration, sine sweep, package testing
How it works
Force output is the headline rating, but sine force and random force are different numbers on the same machine, and shock force is different again. A machine advertised at 20 kN sine may be 18 kN random and 40 kN shock.
What to check before you buy
- Sine, random and shock force ratings, all three separately.
- Usable frequency range.
- Displacement stroke, peak to peak. Low frequency testing runs out of stroke long before it runs out of force.
- Maximum payload and table size, including any fixture. The fixture often weighs more than the specimen.
- Shock capability in g and pulse duration, if you need it.
- Amplifier power and cooling, air or water.
- Controller and software, and whether it runs the standard you are being asked to meet.
- The standard itself: MIL-STD-810, ISTA, IEC 60068, ASTM D4169 all demand different things.
Published free, no form. If a supplier will not answer one of these in writing, that is worth knowing before you order.
Common confusion
A drop or shock machine does one thing very well and costs far less. If your requirement is a package drop test or a bump test, you may not need a shaker at all.