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Linear laser interferometer measurement system​

Linear laser interferometer

Performance, versatility, ease of use

HPI-3D linear laser encoder measurement system is the result of more than 20 years of experience in of high-precision laser interferometry field. The interferometer represents a “know-how” in the field of laser measurements and with the best parameters. All this goes along with the highest quality, a very rich set of accessories and options, ease of use and compactness. Instructions and full version of the software are available in our download page.

Interferometer features

Basic resolution of the laser interferometers based on He-Ne laser is 158.2 nm. The HPI-3D uses a special combination of heterodyne and homodyne optical configurations to achieve a basic resolution of 100 pm for single-pass optics and 50 pm for double-pass optics with excellent sub-nanometric measurement linearity. HPI-3D signal processing path provides the highest resolution at any measured speed.

When connecting HPI-3D over USB port it is possible to monitor vibrations of a measured object at frequencies up to 100 kHz with resolutions down to pico-meters. Such parameters allow using the instrument in the field so far reserved for specialised laser vibrometers. Special optics with very light reflection index can be used additionally to improve accuracy.
CNC or CMM machine are mechanical devices that requires calibration from time to time. Proper tools like HPI-3D offer unique machine tools analysis capability. Parameters like positioning, velocity or acceleration are picked at really high rate. The information gathered by HPI-3D can be used for further analysis with specialised mathematical software or for machine calibration.
In today’s industry exists a clear trend of increasing processing speed of CNC machines. Testing of such machines requires an instrument capable to handle high or very high velocity. HPI-3D with its unrivalled high frequency architecture offers a standard measurable velocity of ± 7 m/s and an option of an unimaginable ± 20 m/s!
HPI-3D Laser head on a tripod
The HPI Software has always being and is developed on the base of constant feedback from users. It is simple to use yet with rich set of features. Measurements and analysis are performed from a single application with common interface – fast and easy!
Full  version of the HPI-3D software is available for download on our webpage. The update is completely free. We provide lifetime software support.
The most difficult part of each laser interferometer measurement is alignment of the laser beam path. One of built-in alignment tools in HPI-3D is laser head position indicator. It shows the pitch and yaw angles. It helps to reduce setup time, especially on more complex machine tools.
An important part of the HPI-3D system is beam position subsystem. It allows instantaneous measurements in three directions (i.e. along and perpendicular to the laser beam). 3D subsystem is responsible for improvement of laser measurement accuracy, and provides straightness data and responds for simple beam path alignment.
Compact laser head is a self-contained unit. Just content it to PC and power line, no extra cable or control units are required.
HPI-3D is a highly integrated device with many functional modules placed in a sturdy case. The device is designed to be easily transportable. Inside the case laser with linear and angular optical components, environmental sensors, power supply and necessary cables can be placed. The whole system weights less than 10 kg.
This is a device allows many different types measurement. Full functionality of the laser interferometer depends on the utilised optical configuration. Usually simple linear configuration is used but there exists a number of possibilities. Additional optical elements are offered either as standard components or as an accessory. No software or hardware update needed.
The interferometer can function as a replacement of magnetic and glass scales, i.e. as a high-precision laser encoder. The encoder output is fully configurable from the HPI Software with simultaneous differential digital and differential analog outputs. Maximum frequency of the digital output can be as high as 25 MHz.
For certain applications even rich functionality of HPI Software may be not enough. In those cases user can develop its own software to utilise functionality of the HPI-3D system. All necessary drivers and program API are available.
Versatility of the HPI-3D reaches new limits with over a dozen pin user configurable digital input/output port. The functionality of those pins can be modified at any time with the use of HPI Software and is stored in non-volatile memory. Thence, laser head pins сan be used e.g. to drive stepping motor or to monitor external sensors state.
An inherent and very unique part of the HPI-3D is the subsystem for of the laser beam position measurement in space. The instrument is capable of simultaneous measurements of the retroreflector position change in all three directions making rapid estimation of machine geometry possible with the use of simple linear optics. Machine tool geometry parameters like straightness, squareness or parallelism can be easily assessed.
High precision laser interferometry requires air temperature, pressure and humidity sensors. Additionally a few base temperature sensors are also recommended. HPI-3D integrates, in standard configuration, an environment compensation unit together with maintenance free wireless sensors.
New feature allowing simultaneous measurement of laser interferometer and high accuracy electronic spirit level in the HPI Software. It is now possible for example to control the level, pitch, yaw or roll during single yet simple measurement!

Performance​

No more limits during measurements! Linear measurement system HPI-3D optimises the parameters available in modern laser interferometers. Extremely high speed of movement, ultra high resolution and high sample rate make the device suitable even for very demanding applications.

Interferometer encoder HPI-3D can measure moving objects with velocity up to 7 m/s with standard resolution of 100 pm. Automatic compensation for environmental conditions is performed 100,000 times per second. Frequency vibrations up to 50 kHz can be easily measured. Even better parameters are available upon request!

Versatility

Although there is no universal measurement device, the HPI-3D comes close. The instrument can be used to measure long (tens of meters), extremely short (hundreds of pico-meters) distances and  geometry of the machine, to detect very fast and indefinitely slow movements. The system can monitor vibrations, measure angles, compare distances and many more. The laser device can be used in scientific laboratories, machinery industry workshops and outdoors. Not only can it be controlled by computer, tablet or smartphone, but user can modify its functionality in many ways.

Ease of use

The HPI-3D was designed with an emphasis on ease of use and portability. The instrument has built-in wireless connectivity and can work with or without a PC connection. It can be mounted directly on the measured object (e.g. inside a machine) simplifying the measurement path and saving alignment time. The laser is available in a small, rugged carrying case that offers excellent portability. The easy-to-use and powerful PC software makes using the entire device an easy task even for inexperienced users.
Linear interferometer in case
Measurements available with our linear interferometer
  • Positioning of CNC and CMM machines
  • Flatness measurement
  • Axis parallelism measurements
  • Angular positioning
  • Vibration measurements
  • Squareness measurements
  • Small angle measurements
  • Straightness measurements
  • Dynamic measurements with internal or external strobe light
Servicing operation available with our measurement equipment
  • Machine geometry inspection
  • Fast evaluation of machine geometry
  • Ball screw encoder inspection
  • Machine maintenance
  • Vibration measurements
  • Variety of laboratory applications

Why should I calibrate my CNC machine?

CNC machine encoder calibration is essential to make sure that the accuracy and precision of the machine is up to the standard. As an encoder is the crucial component of any machine, as it provides position feedback of the machine’s essential components, such as the spindle, tools and table. That is why the encoder calibration is critical to achieve the precision required. Laser encoder is an indispensable tool on such a task. Here are a few reasons why the machine will benefit from laser interferometer calibration:

  1. Machine wear and tear: a CNC machine, being a mechanical device, is a subject to wear and tear over time, which will lead to a decrease in accuracy and even repeatability. Regular calibration with our laser interferometer will help to identify these issues early on and mitigate them before they become a real problem.
  2. Accuracy and precision: CNC machines rely on accurate positioning to produce high-quality results. Calibration with a laser interferometer helps to ensure that the encoder readings are accurate and precise and that the controller positions the machine’s tools and the manufactured product in the most precise way possible thus reduces the marriage rate.
  3. Improved efficiency: Accurate and precise CNC machines can produce workpieces with minimal waste and fewer defects that leads to improvement in overall efficiency by reduces the marriage rate which in turn leads to lowering in production costs.
  4. Better than mechanical: Laser interferometer precision is dependent on the accuracy of the laser frequency for the most part and, unlike other measurement equipment, lacks any mechanical parts that are a subject to wear and tear. This allows for even the most complicated measurements to be performed faster and easier, thus with a better degree of precision.
  5. Simple fast and straightforward to use: With electronic alignment technology the device installation is much faster end easier than ever before. Compact size and magnetic base makes the system really portable and our G-code and calibration table generator allows various controller types calibration out of the box with no additional fees.