User Manual
Slam Stick User Manual
Version No. 2.0
6
There are three core product variants shown in Figure 1, the Slam Stick C, X, and S. Each Slam
Stick type has an embedded triaxial accelerometer, temperature sensor, pressure sensor, filters,
battery, storage, and data acquisition electronics.
The differences between the products mainly comes down to the type of accelerometer
embedded in the logger. Each variant comes with a triaxial capacitive MEMS accelerometer (it’s
not standard for the X but available as an add-on). These accelerometers are great for general
purpose testing; but it has some limitations. Specifically, its sample rate (limited to 3,200 samples
per second per axis), resolution, filtering, and noise levels are not good enough for higher-end
engineering applications. But these accelerometers are much lower cost than alternatives and
so Midé is able to offer the Slam Stick C, which only has this type of accelerometer, at a much
lower cost than the X and S.
The Slam Stick X has a triaxial piezoelectric accelerometer in addition to the capacitive DC MEMS
one. This accelerometer offers a higher data quality, wider measurement range options, 5
th
order
Butterworth anti-aliasing filters, and a maximum sample rate of 20,000 samples per second per
axis. Piezoelectric accelerometers are the most popular because of their versatility but they have
two disadvantages. For one, they are AC coupled which means that it can’t measure static
accelerations (like gravity) and generally can’t measure slow (<2 Hz) vibrations (there are some
types meant for seismic applications that have a lower frequency response). Their charge
amplifier can also become saturated during high frequency and amplitude shock events which
will prevent the accelerometer from measuring anything for a second or two as the amplifier
discharges. Thankfully in the Slam Stick X, having the added triaxial MEMS accelerometer helps
offset these disadvantages of piezoelectric accelerometers.
The Slam Stick S has an added triaxial piezoresistive accelerometer in addition to the capacitive
DC MEMS one. This accelerometer offers similar advantages as the piezoelectric: a higher data
quality, wider measurement range options, 5
th
order Bessel anti-aliasing filters, and a maximum
sample rate of 20,000 samples per second per axis. But they have the added benefit of being
capable of measuring static accelerations and low frequency vibrations. They also have internal
gas damping to widen the dynamic range of the accelerometer and prevent it from reaching its
internal resonance. These accelerometers are increasingly becoming more popular but they are
relatively expensive, making the Slam Stick S Midé’s most expensive product variant.
For more information on accelerometer types and what’s best for your application refer to Midé’s
