Graphtec AT Series

AT500, AT0023, AT7500

• Detects microvibration without contact

LASER VIBROMETER

The AT Series Laser Doppler Vibrometer can measure the vibration of an object without contact, by means of the optical heterodyne method. By FM-demodulating the difference in frequency between reference and measured light, the AT Series can detect the speed and frequency of an object's vibration, rendering microvibration measurement possible.

The wide range of AT Series applications includes pickups for DVDs, CDs, and HDDs, vibration analysis of audio equipment, as well as applications relating to the automobile industry, general plant equipment, and micromachines.

Measuring the transmission function of an optial pickup		Measuring the runout of an HDD surface and analyzing the vibration of a slider		Measuring the moving rate and displacement of a scanner stage		Measuring the vibration of a wire bonder capillary

Ease of installation

The AT500 can be easily installed. A laser beam can be focused on the measuring spot simply by installing the AT500 horizontally. Necessary operations and displays are located on the front, which provides user-friendly operation.

Highly accurate vibration measurement for soft or light objects

Non-contact vibration measurement achieves high accuracy without affecting the vibration of the object.

Vibration measurement for small structures

As the diameter of a laser beam spot is very small (approx. 20μm when measured at close range), the vibration of very small structures can be measured.

Easy positioning of focus and reflected light

The dedicated, highly sensitive lens enables comparatively easy sensing, even for a material that dose not reflect a laser beam well. Moreover, the built-in auto-focus function automatically selects the optimum focal point.

Scalable functions

As the AT500 has a single range demodulating function, measurement is enabled simply by connecting it to the output terminal. Connecting to AT3700 or AT3600 demodulation unit, which can be purchased separately, enables a wider range of measurement

Demodulation Unit

The demodulation unit FM-demodulates signals that have O/E-converted by the sensor unit (i.e.,where the optical signals have been converted to analog signals), subsequently outputting signals proportional to the vibration speed of the object of measurement.While the standard function outputs the speed and frequency of vibration, the differential-integral function (an optional feature that can be incorporated in the unit) can integrate speed to calculate displacement and differentiate the speed into an acceleration, outputting the results.

Wide-band demodulation unit

AT3700

A broad measurement range and a rich variety of applications

The measurement frequency range,from DC to 2 MHz, permits the measurement of transitional characteristics from a static state,and of uniform motion and vibration at high frequencies. The measurable speed range is from 0.4μm/s to 10m/s(lower limit of speed:5 kHz LPF). The AT3700 thus permits a broad range of vibration measurements and is applicable to a variety fields.

Various optional features

• Wide-band demodulation function:
  Incorporation this in the unit raises the upper limit of the measurable frequency range to 10 MHz, rendering an ever broader range of measurement possible.
• Differential-integral function:
  Incorporating this in the unit makes it possible to differentiate speed signals from the Laser Doppler Vibrometer into an acceleration and to integrate these into a displacement.

High-sensitivity demodulation unit

AT3600

Improved sensitivity helps overcome difficult measurement conditions

Measurement sensitivity has been greatly improved : the AT3600 is now twice as sensitive as before. This high sensitivity provides for convenient vibration measurement of object that were previously difficult to measure.

Differential-integral function

This feature enables the differentiation of speed signals from the Laser Doppler Vibrometer into an acceleration, and for their subsequent integration into a displacement(speed, displacement, and acceleration can be output at one time).

Scanning-Type Laser Doppler Vibrometer System
AT7500

Enables some points of the small object to measure with high-speed, and surface vibration measurements to display, judge, and to animationize

AT7500 is a surface vibration system which can measure some points of the small object with high-speed, and which can display, judge, and animationize the measurements by using Laser Doppler Vibrometer. Concerning vibration answering frequency, AT7500 can measure it from DC to 1MHz. Also AT7500 can measure vibration quantity for the optional applied vibration signals (speed signals and displacement signals), and judge GO/NG for the rated value.

By using scanning function of laser beam with two axises galvano mirror, AT7500 can measure +/-20mm XY surface.

Moreover, combining scanning function with electric stage (optional) will expandXY surface to +/-45mm.

Measurement area

AT7500 can measure XY surface to Max. +/-45mm to use laser beam scan in combination with electric XY stage (optional) by two axis galvano mirror.

Measurement point

Max. 10,000 points can be measured.

Vibration quantity measurement function

AT7500 can measure vibration quantity of object by set sampling frequency, and judge GO/NO for the rated value.

Data storage

Measurement conditions and measurement data can be saved into CSV file format or ME′ scope file format.