Microscope Maintenance

Customers often ask what they can do when they have problems with lubrication and focusing problems with their microscopes. Here are a few questions along with our suggestions:
Question: What product should I use to lubricate the bearings on the stage of the microscope?
Answer: Each manufacture has their own line of lubricants they recommend. If you bought everyone for each product it would be extremely expensive. We use a product called Super Lube made by Permatex. It should be available from many stores in your area. We use this product on all brands of microscopes that we service.
Question: My stage seems to slip down out of focus for no reason. What can I do to prevent this?
Answer: There are two main reasons for this problem. Either the tension control is too loose, or the main bearing system in the stage mechanics needs some adjustments.
You, as the microscope user, can adjust the tension control. Many microscopes have focus tension controls attached next to the coarse focus control. This control may be the simple type that you can adjust by just using your hand, or it may take a special tool. On Olympus or Nikon microscopes the adjustment is usually on the right side of the scope as the stage faces the user. It is a thin control knob or disc that is placed between the microscope stand and the coarse focus control. All you have to do is turn this device one way or the other and it will increase or decrease the tension on the coarse focus control knob. This in turn will keep the stage from slipping down. Make sure you are not turning the stage lock control, which is normally on the opposite side of the tension controller. If your microscope takes a special tool to adjust the tension. and you have lost this tool, you will need to contact the microscope manufacture or the company you purchased your microscope from and request the adjustment tool.
If the main bearing system needs adjustment you will should contact a qualified microscope repair technician to do this repair.

Microscope Maintenance

Microscope Immersion oil

As magnification increases on a microscope the correction in refractive index is a requirement for finer resolution and brightness. As the light cone passes through the different layers of glass, sample mounting media and air light tends to bend at different angles. In most cases the sequence of the light leaving the substage condenser is glass (1.515nD), air (1.00nD), glass slide (1.515nD), sample, mounting media, cover slip (1.515nD), into the objective lens which is approximately 1.515nD.

Immersion oil has a refractive index of 1.515nD and is applied to the top of the cover slip and then the tip of the oil immersion objective is then immersed into the drop of oil. This completes the “optical connection”.

The resolution obtained is directly related to the angular aperture (AA), the larger the A.A. having a wider cone with more scattered (oblique) rays. Unless there is a homogenous light path, the most oblique rays are lost to internal reflection inside the glass slide or cover slip. The use of immersion oil permits full use of the resolving power of the objective lens. Immersion oil objectives increase the resolution by approximately fifty percent over dry objectives of equivalent focal length.

The resolving power of an optical system is figured by averaging the numerical aperture (N.A.) value of the objective and the working N.A. of the condenser.

The acid value of immersion oil should be very low. If not then the higher acid content can lead to eventual deterioration of the metal parts of the objective lens or worse yet the dissolving of the cements used to manufacture the lens. This is turn leads to a leakage problem as immersion oil is wicked up into the interior of the lens.

Viscosity of the oil is up to the user. Lower viscosities tend to run and spread all over the microscopes requiring more clean up. Higher viscosities are more practical and not as messy. Very high viscosities are used for instruments that are mounted on slight angles.

When applying immersion oil use only the amount required for the individual slide. Too much oil does not help with the optical performance as much as it requires more clean up. Not enough oil will not allow a good optical contact with the objective.

Which oil is the best? Our choice is Cargille Immersion Oil. It is manufactured with the best materials. Immersion oil must meet the design requirements of older microscopes and become the design criteria for new instruments.

Author Name: Rowland Brasch: Nationalmicroscope.com

Microscope Immersion oil

ATAGO PRM-100a In-Line Refractometer

The successful series of In-line digital refractometers by Atago Company LTD has added a new product, and it is being carried by National Microscope Exchange. The newly released ATAGO PRM-100a digital refractometer has replaced the popular older style PRM-85 and PRM-85SE instruments, which were a mainstay of the company for years. Atago Company is one of the most respected world leaders in manufacture of refractometer products according to National Microscope Exchange President Rowland Brasch.

“The newly designed PRM-100a In-Line refractometer continues on in the tradition of excellent ATAGO products which have made it a world leader in refractometry,” said Brasch. “The new ATAGO-PRM-100a incorporates the accuracy and ease of use found in the less expensive model CM-780N, but adds the features of a higher degree of accuracy along with the capability to measure refractive index as well as brix.”

The new PRM-100a In-Line refractometer has accuracy readings of +/- 0.05% brix and +/- .00010 for refractive index, and has two options for setting the minimum indication decimal place, as well as the ability to set a User-Defined Scale (input via RS-232C). This instrument is easily connected to your system by attaching the unit to a piping system to monitor food or beverage production, pharmaceutical production, industrial fluid, washing devices, dilution/mixing devices, etc. The in-line refractometer will continuously monitor water content and mixing ratio with successive measurements of refractive index, Brix, or concentration.

“ATAGO refractometers such at the PRM-100a are popular with users because of their accuracy and ease of use,” said Brasch. “The PRM-100a In-Line refractometer is more accurate than other ATAGO In-Line refractometers, making it more attractive to users.”

You can learn more about National Microscope Exchange products by visiting www.nationalmicroscope.com or by calling 800-851-7635.

Author Name: Rowland Brasch: Nationalmicroscope.com

ATAGO PRM-100a In-Line Refractometer

Digital Microscope Cameras

The successful line of digital microscope cameras by Vee Gee Scientific has added a new version of its H-Series to its VanGuard microscope accessory line., as carried by National Microscope Exchange. The newly designed VanGuard H-Series digital microscope camera system has replaced the popular older style H-series camera system, which was a mainstay of the company for years. VanGuard is a growing and respected importer of quality microscopes and accessories according to National Microscope Exchange President Rowland Brasch.

“The newly designed H-Series digital microscope camera system continues on in the tradition of excellent VanGuard products which have made it a leader in quality and affordable microscopes,” said Brasch. “The new H-series system incorporates the accuracy and ease of use found in the older style H-series which gives you the digital microscope camera, software, adapters and cables required to connect it to your computer.”

The H-Series digital cameras from VanGuard produce high-definition live images and video for the documentation and archival of clinical, life science, and material science laboratory analysis. With resolution of 1600 x 1200 (UXGA) and the included image capture software suite, the H-Series cameras are a perfect match for nearly any scientific application. Equipped with ½" CMOS image sensors, VanGuard H-Series digital cameras deliver exacting image clarity and color. In addition, H-Series digital cameras come standard with the following features: still & video capture modes, automatic/manual exposure control, manual gamma control, and automatic/manual white balance control.

“Vanguard products such at the H-Series digital microscope camera system are popular with users because of their accuracy and ease of use,” said Brasch. “The H-Series system is more affordable than some of the other products in the digital microscope camera product line, making it more attractive to cost-conscious users.

You can learn more about National Microscope Exchange products by visiting www.nationalmicroscope.com or by calling 800-851-7635.

Digital Microscope Cameras

How Polarized Light Works in a Microscope

By Rowland Brasch

Normal light waves go in every direction. In a polarizing microscope the light waves are managed using two polarizing filters. One is called the analyzer and the other is the polarizer.

One way to understand how to create polarized light is to pass ordinary light, containing light waves that are vibrating in all directions, through thin slots cut in a piece of paper.

If the slots were aligned vertically then only the vertical light waves would pass through while the others would not. The vertical lights coming out of the slots are considered polarized light waves. These light waves in turn then illuminate the sample, usually crystals of some type. After passing through the crystal they are now out-of-sync because they moved at different velocities within the mineral. Once the light waves pass through the analyzer the colorations of the crystal provide identification of such samples.

Good examples of polarizing microscopes would be the Meiji ML9420 or the VanGuard 1242MM.

Most minerals are viewed where these polarizing filters are turned at 90 degree angles to each other. Polarizing microscopes are used to observe minerals and crystal formations. Applications can be in the clinical field for gout, law enforcement for drug analysis, industrial testing and geological applications.

How Polarized Light Works in a Microscope

Microscope Maintenance | Microscope Repair

Customers often ask what they can do when they have problems with lubrication and focusing problems with their microscopes. Here are a few questions along with our suggestions:

Question: What product should I use to lubricate the bearings on the stage of the microscope?
Answer: Each manufacture has their own line of lubricants they recommend. If you bought everyone for each product it would be extremely expensive. We use a product called Super Lube made by Permatex. It should be available from many stores in your area. We use this product on all brands of microscopes that we service.

Question: My stage seems to slip down out of focus for no reason. What can I do to prevent this?
Answer: There are two main reasons for this problem. Either the tension control is too loose, or the main bearing system in the stage mechanics needs some adjustments.

You, as the microscope user, can adjust the tension control. Many microscopes have focus tension controls attached next to the coarse focus control. This control may be the simple type that you can adjust by just using your hand, or it may take a special tool. On Olympus or Nikon microscopes the adjustment is usually on the right side of the scope as the stage faces the user. It is a thin control knob or disc that is placed between the microscope stand and the coarse focus control. All you have to do is turn this device one way or the other and it will increase or decrease the tension on the coarse focus control knob. This in turn will keep the stage from slipping down. Make sure you are not turning the stage lock control, which is normally on the opposite side of the tension controller. If your microscope takes a special tool to adjust the tension. and you have lost this tool, you will need to contact the microscope manufacture or the company you purchased your microscope from and request the adjustment tool.

If the main bearing system needs adjustment you will should contact a qualified microscope repair technician to do this repair.

Author Name: Rowland Brasch: Nationalmicroscope.com

Microscope Maintenance | Microscope Repair

ATAGO Refractometers

ATAGO Company LTD. is an ISO 9001 certified manufacturer, and has been the leading innovator in refractometer technology for over 70 years. The company has developed a full line of refractometers and polarimeters for measuring liquid concentrations in the lab, as well as a variety of hand held refractometers to use out in the field or on the production line. ATAGO refractometers and polarimeters can be found in over 155 countries, and are not only used in food and beverage industries, but also in research laboratories, universities, clinics and industrial settings.
The history of Refractometers began with a basic model – a simple analog instrument. Today, refractometers are highly sophisticated instruments due to the advancement of technology and the incorporation of high precision electronics into a refractometer.
ATAGO is constantly researching various and unique needs in the market, developing new and innovative products to meet the demands. In it’s quest for solutions to satisfy it’s customers needs, ATAGO continually strives to produce and bring to the market new instrumentation, which has never been seen or considered before through their in-depth research and development.

The USA office, located in Bellevue, Washington in the heart of the thriving Great Northwest, ATAGO U.S.A. is now in a better position to provide technical and sales support to all our valued distributors and end-users in North, Central and South America. ATAGO U.S.A. is committed to responding quickly and efficiently to every customer inquiry, and comprehensively researching their dynamic market place.


Author Name: Rowland Brasch: Nationalmicroscope.com

ATAGO Refractometers

In-Line Refractometers

In-Line refractometers are designed to monitor and control the concentration of dissolved solids or water soluble liquids in your process lines. These instruments can be incorporated in piping of manufacturing plants, liquid mixing devices, and washing apparatuses to continuously measure the concentration of various liquids. In-Line refractometers are suitable for use in the control of mixing, concentration, fermentation, and control of the concentration of water-based or alkali-based detergent, etc.

The light from an LED source is transmitted by a fiber optic onto one side of a measuring prism and internally reflected to the interface of the prism and the sample liquid. A portion of this light beam is reflected back onto the opposite side of the prism at an angle which depends on the refractive index of the liquid at the interface. The position of this reflected beam, as it exits the prism, changes with the angle of reflection (which depends on the refractive index of the sample). A linear diode array is used to accurately detect the varying position of the reflected beam, and this position is calibrated with respect to refractive index. As there are no moving parts with in-line refractometers, only precise optical and electronic elements, the calibration is very stable, repeatable and accurate.

To connect the in-line refractometer to your system you simply attach the unit to a piping system to monitor food or beverage production, pharmaceutical production, industrial fluid, washing devices, dilution/mixing devices, etc. The in-line refractometer will continuously monitor water content and mixing ratio with successive measurements of refractive index, Brix, or concentration.

The ATAGO Model PRM-100α In-Line Refractometer is just such an instrument. It can provide the following:

• Wide range 0.0 to 100.00% Brix range
• Improved measurement accuracy: Brix ±0.05%, nD ±0.00010
• Two options for setting the minimum indication decimal place
• Simple two-piece construction: detection section and operation display section
• Easy-to-read color display panel.

Author Name: Rowland Brasch: Nationalmicroscope.com

In-Line Refractometers

Antifreeze Refractometers

Low temperatures leading to freezing conditions can, if not managed correctly, often result in serious damage to plant and equipment, chillers and engine cooling systems. System blockages, cracked pipes and unwanted fluid loss can be expensive both in terms of operational down-time and ultimate repair or replacement costs. It is therefore essential that systems are properly protected and antifreeze levels are periodically tested. Testing of antifreeze concentrations for automotive and industrial applications has been made easier by the use of antifreeze refractometers.

The antifreeze/battery refractometer is designed for testing the refractive index or concentration of battery fluids, antifreeze liquid and cleaning fluids that works on the critical angle principle. Antifreeze refractometers utilize lenses and prisms to project a shadow line onto a small glass reticule inside the instrument, which is then viewed by the user through a magnifying eyepiece.

In use, a sample is sandwiched between a measuring prism and a daylight plate. The reading is taken when a shadow line crosses the scale from the shadow line formed between the illuminated area and the dark area then a shadow line crosses the scale. With the indication of the percentage you may know which temperature the fluid will be frozen for both propylene glycol and ethylene glycol. It can also be used for checking the strength of electrolyte solution batteries.

Refractometers represent the most accurate conventional testing method available for determining freeze point and concentration of engine coolants and antifreeze solutions. Don't be misled by hydrometers or freeze-point test strips, which are not accurate enough to be useful.

One of the best instruments to test these solutions is the ATAGO Antifreeze Refractometer model Master BCF. This refractometer has an exclusive scale for measuring specific gravity of battery fluid and for checking the freezing temperature of ethylene glycol and propylene glycol which are used as antifreeze mixture in automobiles, thermal catalyst for solar power systems and other industrial applications. The Master BCF is easy to use and accurate for testing in the field

Author Name: Rowland Brasch : Nationalmicroscope.com

Antifreeze Refractometers

Inverted Microscopes

Most microscopes that you see in a typical laboratory environment are compound microscopes. They are designed with objectives on a rotating nosepiece mounted above the stage, and the light source and condenser below the stage. They are most commonly used for viewing samples that have been fixed to a flat slide.

In certain applications it is necessary to look at live, unfixed samples. A more practical microscope design to use is the inverted microscope. An inverted microscope is a microscope with its light source and condenser on the top, above the stage pointing down, while the objectives and turret are below the stage pointing up. Inverted microscopes are useful for observing living cells, tissues or organisms at the bottom of a large container (such as a tissue culture flask). This allows you to examine the specimen under more natural conditions than on a glass slide, as is the case with a conventional compound microscope. You can place a Petri dish or other container on the stage and view the samples from below, thus not disturbing their more “natural” states. Larger, covered samples are less susceptible to evaporation and increases in temperature, thus preserving suitable living conditions for the specimen you are viewing.

Because of the fact that you have to look through thicker containers you often find the objectives to be long working distance or ultra-long working distance. These objectives have been corrected for observing samples that are further away than what you normally see on a compound microscope. The image may not be quite as clear as when you are looking at a perfectly flat slide. You may want to use a plastic Petri dish rather than a glass one as the plastic dishes are thinner and more uniform. Most inverted microscopes will have objectives that range from 4-40X, with 60X being an added option. You do not usually find inverted microscopes that incorporate 100X objectives.
Inverted microscopes can be configured for work in electrophysiology, in vitro fertilization, micromanipulation, high-resolution DIC, video-enhanced observations, and a variety of advanced fluorescence techniques. Motorized accessories can include shutters, filter wheels, revolving nosepieces, fluorescence block turrets, focus drives, and condensers. Inverted microscopes also allow you to add advanced objectives for water immersion, ultraviolet excitation, and phase contrast. Prices for inverted scopes vary according to the number and types of accessories you add to them, just as in compound microscopes.

The fundamental advantage of an inverted microscope is that it allows you to accept a container with a large and relatively long-lived diverse culture of live organisms without any preparation. This can be invaluable to work which requires the sample to be alive and in as natural an environment as possible.

Author Name: Rowland Brasch : Nationalmicroscope.com

Inverted Microscopes

Used Microscopes

Remember back to your school days when you first saw amoeba swimming around in pond water? You thrilled to seeing the microscopic organisms moving around, bumping into each other. Now you want to share that memory with your children or grandchildren as they grow. But you don’t want to spend their college money on a new high-priced microscope, so what can you do? No problem – you can now find many microscopes that are either used or demo models at a much more reasonable price. But first you need to determine what type of a used microscope you want: compound or stereo/dissecting.

The most common microscope is the compound microscope. It is the one most people visualize when they think about microscopes. It comes with one eyepiece called a monocular; two eyepieces called a binocular or it might have an additional camera tube and is called a trinocular. It has a number of objectives (the lens closest to the object being viewed) of varying magnification mounted in a rotatable nosepiece. It uses a light source beneath the stage to illuminate slides. These microscopes are generally used to view very small objects such as cells or bacterium mounted on slides. Magnification of these scopes range from 40X up to 1000X. Actual magnification can be figured by multiplying the power of the eyepiece by the power of the objective lens.

The other type of microscope is called a stereo or dissecting microscope. It uses two eyepieces and two paired objectives. There are models that have full zooming capability and models that just have only two magnification settings. It is particularly useful for biologists performing dissections, technicians building or repairing circuit boards, paleontologists cleaning and examining fossils or any one who needs to work with their hands on small objects such as rocks & bugs. It may use a built in light source from above, below, or none at all. Magnification is usually from 10X to 40X.

By researching and purchasing used microscopes you open up a much greater range of instruments available to you. You can now purchase an instrument with many more accessories for much less money. Just make sure to do your homework ahead of time so that you know what to expect for the money you pay.

Author Name: Rowland Brasch : Nationalmicroscope.com

Used Microscopes