Asbestos Microscopes

The BMDZ is a full zoom trinocular stereohead with a magnification range of x7.5 to x45 with the x10 widefield eyepieces. The range may be extended to include x3.5 to x180 with additional objectives and eyepieces. The zoom mechanism is operated by side arm control knobs. The eyetubes have full interpupillary and dioptric adjustment and eyecups are supplied as standard. The unique features of this stereohead are the fact that the trinocular tube shares the images with the binocular eyetubes which allows the microscope to be used at the same time as the image can be viewed on a monitor or PC by others. Providing the correct adapter is used the two images are parfocal which makes the BMDZ an ideal stereomicroscope for teaching and demonstration. In addition the zoom mechanism has a lock control so that a predefined magnification can be set. This is particularly useful in an industrial environment where the instrument may be used by several operators.
A plain stand without lighting. Pole coarse focus with a rack and pinion finer focus and a large working area with central dissection plate and stage clips (removable). A freestanding dual gooseneck LED lighting stand is included. There are of course several other zoom stereomicroscopes in our range and a link to them is below. However we recommend this the BMDZ as the feedback from our customers tells us that if fits the air flow cabinets well and does the job.

The identification of asbestos fibres requires the use of a polarising microscope that has a first order red retardation plate and a specialist x10 objective with a back stop. These are known as dispersion lens objectives and were also known by the original manufacturers name as a McCrone objective. These are used to examine the dark field colours shown by fibres that are immersed in various refractive index oils. The Brunel SP250PA is supplied with both a standard x10 and also a dispersion x10 objective together with a standard x20 and x40. All objectives are plan infinity corrected. One of the most important features of any polarising microscope is the illumination system. Crossed polarising filters obviously produces a black background, and the brilliance of the appearance of birefringent objects is dictated by the lighting system of the microscope. The Brunel SP250PA binocular has rheostat controlled quartz halogen illumination, with 6 volt 20 watt lamps located in an easy to reach lamp housing that can easily be accessed from the base of the microscope.

The microscopy requirements for the identification and particle counting of asbestos are exacting, and are covered by the Health and Safety Guidance (HSG) 248 Appendices 1 and 2 of the Health and Safety Executive (HSE). www.hse.gov.uk/asbestos/index.htm is an excellent resource for up to date information and further references. Any suitable microscope must be able to resolve either band 4 on a red label slide (with maybe parts of band 5 visible) or band 5 on a green label test slide (with maybe parts of band 6 visible). The x40 phase objective with a x12.5 eyepiece with a Walton and Beckett graticule is the required combination.
The Brunel ABS320 meets the green label standard using test slide 6609 certificated and confirmed by the HSL themselves. We believe that it is the lowest price microscope on the market to do so. The use of the test slide is required by the HSE to ensure microscopes are properly adjusted when testing for compliance with the UK asbestos control limits. These are robust industrial microscopes finished to a very high standard and with a very modern design. The light source is a Kohler LED unit integral to the base of the microscope. This makes the microscope an ideal instrument for phase contrast applications, and the trinocular ABS320 is, we believe, the lowest priced phase contrast microscope that meets the HSE specification for asbestos fibre counting that is currently available.

This is an excellent carrying case with suitcase style handles and wheels which makes the ABS320 truly portable