Kern OBL 137 transmitted-light microscope, trinocular, Infinity, 40x to 1,000x, 3 W LED

The Kern OBL 137 is a trinocular transmitted-light microscope with Infinity optics, a 3 W LED and pre-centred Köhler illumination. Four Infinity E-Plan objectives ranging from 4x to 100x are mounted on a four-position nosepiece; the HWF 10x eyepieces have a 20 mm field of view. The Butterfly tube has a camera output with a 20:80 beam splitter ratio. Kern regards the OBL 137 as the base unit of a modular system that can be expanded to include dark field, polarisation, phase contrast and fluorescence.

Infinity optics and objectives

In the Infinity system, the light rays run parallel behind the objective before a tube lens forms the image. This leaves space between the objective and the tube lens for additional units without changing the image. The 4x (aperture 0.11), 10x (0.25), 40x (0.65, spring-loaded) and 100x (1.25, oil, spring-loaded) objectives are coated with an anti-fungus coating. With the 10x eyepiece, the total magnification ranges from 40x to 1,000x. According to the data sheet, the field of view ranges from 0.2 to 5 mm.

Köhler illumination without centring

The Abbe condenser with an aperture of 1.25 is fixed, pre-centred and can be focused by height adjustment. Together with the field diaphragm and the aperture diaphragm, this results, according to Kern, in a simplified Köhler illumination in which the centre cannot be adjusted. The 3 W LED has a colour temperature of 6,000 K and is continuously dimmable. Filters can be used.

Tube, mechanical stage and focusing

The Butterfly tube is inclined at 30° and can be rotated through 360°. The interpupillary distance can be adjusted from 50 to 75 mm, while the dioptre adjustment operates on one side from -5 to +5. The large mechanical stage has a specimen holder capable of accommodating up to two specimens at the same time. Focusing is achieved via a coaxial coarse and fine focus mechanism on both sides; the fine focus mechanism adjusts in increments of 0.002 mm. According to the data sheet, torque control is available. Kern also mentions a robust base, which enables safe operation.

Expansion with additional units

According to the data sheet, the contrast methods dark field, polarisation, phase contrast and fluorescence are optional. To this end, the brochure lists a dark field condenser (OBB-A1422), a simple polarisation unit (OBB-A1277), phase contrast sets with a PH condenser, PH sliders and PH objectives, as well as a 100 W HBO fluorescence unit (OBB-A1153) and a 5 W LED fluorescence unit (OBB-A1157). Which parts fit together should be clarified before ordering.

Power and dimensions

The plug-in mains adaptor operates at 100 to 240 V at 50/60 Hz and 0.3 A; the device is supplied with 5 V at 1 A. The barrel plug is positive on the inside, with an outer diameter of 5.5 mm and an inner diameter of 2.5 mm. The microscope measures 394 x 185 x 377 mm and has a net weight of approx. 7 kg.

Typical applications

• Haematology, urology, gynaecology and dermatology
• Pathology, microbiology, parasitology and immunology
• Water analysis, sewage treatment works and breweries
• Veterinary practices, as well as inpatient and clinical laboratory facilities
• Public health authorities, training centres and universities

As samples, Kern names translucent and thin, low-contrast and demanding specimens, for example living mammalian cells, bacteria and tissue.

Technical details

Scope of delivery

• OBL 137 microscope with trinocular Butterfly tube
• Two HWF 10x eyepieces
• Infinity E-Plan objectives 4x, 10x, 40x, 100x
• Plug-in mains adaptor with Euro plug
• Dust cover
• Eyecups
• Multilingual operating instructions

Warranty

According to Kern & Sohn, this microscope comes with a 3-year warranty. Kern grants 3 years on products with a list price of €500 or more and 2 years on products below that and on components; wear parts such as batteries and rechargeable batteries are excluded. Warranty repairs are carried out by Kern or by a Kern dealer.

Downloads

• Operating instructions Kern OBL-1 (PDF)

Regulatory information

As an electrical device, the microscope falls under the ElektroG. The manufacturer Kern & Sohn GmbH is registered under the WEEE registration number DE 80821200. How to return old appliances is described on the page Environment and disposal.

Individual requirements and procurement service

Eyepieces (OBB-A1351 WF 10x, OBB-A1448 HWF 10x, OBB-A1617 and OBB-A1618 HWF 10x with 0.1 mm scale, OBB-A1354 WF 16x), the objectives OBB-A1655 (2x), OBB-A1250 (20x), OBB-A1270 (60x) and OBB-A1437 (100x water), the filters OBB-A1165 (yellow), OBB-A1183 (grey) and OBB-A1188 (green), the OBB-A1422 dark field condenser, the OBB-A1277 polarisation unit, phase contrast units (OBB-A1215, OBB-A1217, OBB-A1219, OBB-A1213), PH plan objectives (OBB-A1390, OBB-A1391, OBB-A1392, OBB-A1393), the PH condenser OBB-A1398, the PH sliders (OBB-A1399, OBB-A1400, OBB-A1401, OBB-A1402), the fluorescence units OBB-A1153 and OBB-A1157, the dust cover OBB-A1388, the cleaning spray OCS-A1101 and the cleaning kit OCS 901 are also available. For the camera connection, Kern lists the C-Mount adapters OBB-A1514 (1x) and OBB-A1515 (0.5x), as well as the ODC 241, ODC 251, ODC 825, ODC 832, ODC 841 and ODC 854 cameras. A C-Mount adapter is required to connect the camera. The complete set with camera is available as the OBL 137C825 and OBL 137C832. Enquiries are handled via our procurement service.