LDT with Crimps Vibration Sensor/Switch

LDT0-028K Piezo Vibration Rev 1

www.meas-spec.com

10/13/2008

2 of 4

examples of properties

Four different experiments serve to illustrate the various properties of this simple but versatile component.

Experiment #1

the crimped contacts pushed through a

printed-circuit board, the LDT0 was

soldered carefully in place to anchor the

sensor. A charge amplifier was used to

detect the output signal as vibration from

a shaker table was applied (using a

charge amplifier allows a very long

measurement time constant and thus

allows the "open-circuit" voltage

response to be calculated). Small

masses (approximately 0.26g

increments) were then added to the tip of

the sensor, and the measurement

repeated. Results are shown in Table 1

and the overlaid plots in Fig. 1. Without

adding mass, the LDT0 shows a

resonance around 180 Hz. Adding mass

to the tip reduces the resonance

frequency and increases "baseline"

sensitivity.

TABLE 1: LDT0 as Vibration Sensor (see Fig 1)

Added Mass

Baseline

Sensitivity

Sensitivity at

Resonance

Resonant

Frequency

+3 Db

Frequency

0

50 mV/g

1.4 V/g

180 Hz

90 Hz

1

200 mV/g

4 V/g

90 Hz

45 Hz

2

400 mV/g

8 V/g

60 Hz

30 Hz

3

800 mV/g

16 V/g

40 Hz

20 Hz

Experiment #2

amplifier to obtain "open-circuit" voltage sensitivity,

the output was measured for controlled tip

deflections applied to the sensor (supported by its

crimped contacts as described above). 2 mm

deflection was sufficient to generate about 7 V.

Voltages above 70V could be generated by

bending the tip of the sensor through 90° (see

Table 2, Fig. 2).