HUD300 Goniometer
Components and Options
As a bespoke instrument, the HUD300 Gonio offers modular parts that can be selected and interchanged to explore a wide range of physical scenarios using one device. This section outlines the key standard components, along with possible customization options.
The TMc300 Monochromator
The monochromator is one of the anchors of the system’s precision, with Bentham drawing on over 40 years of in-house monochromator development. The HUD300 Gonio utilizes the TMc300 Single Monochromator—a 300 mm focal-length Czerny-Turner design spanning 200 nm to 30 µm. Various customization options, including different gratings, coatings, slit configurations, and order sorting filters, allow you to tailor the instrument’s performance to your specific application requirements.
Probe Beam Source
The probe beam originates from a 250 W quartz halogen bulb enclosed with an optical chopper and cooling fans. It is powered by the Bentham 610 Current-Stabilised Lamp Power Supply—a high-power current source providing excellent stability. This setup delivers a probe beam intense enough for accurate optical density measurements after monochromation.
The 610 constant current power supply delivers exceptional stability and reliable long-term performance across Bentham’s range of incandescent and xenon illuminators as well as calibration standards.
Collimator
The collimator generates a uniform, parallel beam of light, ensuring the sample’s active area is fully illuminated. As the incident angle and beam diameter significantly impact the output beam geometry and detector location, collimation is a key consideration.
Standard Configuration
The HUD300 Gonio comes equipped with a customized Bentham COL_1 collimator, closely modeled on the standard COL_1 design. This two-lens system features:
- Three interchangeable apertures for throughput and power optimization
- An adjustable iris for setting the beam diameter
- An internal aperture to balance divergence and power
HUD Mode Integration
In the standard system, the collimator is mounted on a motorized vertical track. By adjusting the collimator’s vertical position and the sample's horizontal position on the sample stage, the instrument can automatically scan the beam across the surface of the sample.
Sample Positioning Assembly
The Sample Positioning Assembly holds the surface or device under test. It features:
- A base plate on a precision track for fine-tuned horizontal displacement
- A motorized revolving section for high-precision angular rotation
Customizable Base Plate
The base plate’s generic structure supports a wide range of surface setups and can be customized with specific fittings to accommodate unique experimental needs. Its robust design allows for virtually unlimited weight capacity, making it suitable for heavier samples or multi-layer assemblies.
Integrated Motor Control
Both the horizontal track and revolving section can be manually adjusted if desired. However, when operated through the BenWin software package, they can automatically reposition to the vertical eye displacement (VED) and viewing angle specified in the software settings, ensuring accurate and repeatable measurements.
Detector Positioning Assembly
The detector is mounted on a dual-motorized arm. One end is connected to the Sample Positioning Assembly for angular movement, while the other end includes a motorized vertical track for vertical displacement. This configuration enables 3D positioning of the detector so it can intercept transmitted or reflected light at the correct location.
All motorized components may be controlled manually or through BenWin software, allowing for precise, repeatable measurements under either scenario. The DH-Si detector comes as standard in the HUD300 configuration.
Acquisition Electronics
Measurements in the HUD300 Gonio are performed in AC mode, using a DH_Si detector coupled to a 477 transimpedance amplifier. The signal is then directed to a 496 DSP lock-in amplifier, which includes an integrated A/D converter for digitization. This setup provides high sensitivity and noise reduction, ensuring precise, stable measurements across a wide range of operating conditions.
