LED Upgrade for Polyvar Microscope

The aim here was to provide a retrofit solution to upgrade the illumination of a Reichert-Jung Polyvar MET microscope, owned by the University of Cardiff.

Background

The Reichert Polyvar range of microscopes (AKA American Optical Ultrastar) were produced with high end optics that maximized optical resolution. They were precisely machined for robust yet simple operation, with brilliant accuracy. This microscope is still very well regarded and sought after, despite no longer being made. Described as “The Rolls Royce of microscopes” by our own Managing Director and former Reichert-Jung sales manager, Eric Best.

However, the illumination system hasn’t stood the test of time in the same way the microscope has. The Polyvar MET / BIO was equipped with a standard halogen light source. Unfortunately, this has disadvantages when compared to modern day LED solutions, specifically colour temperature, performance consistency, lifespan, and energy efficiency.

Things to consider

So, the task was set to manufacture an LED upgrade for Polyvar. The version described and pictured here has been developed with the benefit of two very different previous incarnations. These previous versions helped me develop the final design you see here. The main difficulty to overcome was that the halogen bulb inside the Polyvar had a high lumen output of approx 2550lm from a 12v 100W bulb. This is not commonly matched by standard LED’s and the feedback was that our other incarnations of proposed solutions lacked power. For this final version the LED array was built to have a Lumen output of ≥ 3000lm. Therefore exceeding what was included as standard by the manufacturer.

Another difficulty to overcome was the delivery system. Separate / Boxed LED light sources that deliver light to an optical system by fibre optic cable, suffer form attenuation. So, the full lumen output of the LED array never reaches the optical path. We needed power, so I decided a directly placed LED solution was needed, so nothing is lost.

Final Design

The design was realised and made purposely robust, simple, and easy to install.

Main Specifications

• In situ LED unit with Polyvar Microscope Interface
• ≥ 3000 Lumen Output Power
• 5700k Pure White Colour Temperature
• 0-100% Intensity Adjustable
• 50,000-Hour Lifespan
• Fan Cooled
• Collimation Lens Included
• Easy Retrofit Interfaces

Installation Overview

1. Remove the heat sink fins from top of the microscope, just lift off. This leaves access to the Halogen bulb.
2. Remove Halogen Bulb, simply pulls out of socket.
3. Attach our retrofit plate which has simple thumb screws to secure to sides of the Polyvar body.
4. Attach LED unit to the plate via grub screws, power up with PSU included, and all is connected.

Overall, the Cardiff University users I worked with were very pleased with the illumination upgrade provided, and happy that Best Scientific were able to extend the life of their Polyvar MET microscope.

We can also offer a Camera coupler that can be seen in some of the images attached. This is modular and adaptable to accept for various scientific grade C-Mount cameras, with sensor sizes of 1/3” 1/2” 2/3” and 1” We can also offer microscope to camera adapters to link the Polyvar to Digital SLR cameras.

If this is a solution that will benefit your Polyvar MET or BIO microscope please do contact James Best of Best scientific via this website or directly via  james@bestscientific.co.uk