Lab Test 1 part 1
| Question | Answer |
|---|---|
| What two adjustments can be made to the condenser? what effect do these adjustments have on the image? | Answer: the condenser high and diaphragm can be adjusted. illumination of the specimen is increased when the condenser is raised and the diaphragm is opened. |
What do adjustments can be made to the condenser?
It can be moved up and down the diaphragm with in the condenser can regulate amount of light coming through. B. If not adjusted properly it will limit resolution.
What is condenser adjustment?
The condenser lens adjustment knob is located below the specimen stage and on the left side. It allows the user to move the condenser lens assembly up or down. As you move the condenser lens up, closer to the specimen, it concentrates (condenses) more light on your specimen.
Why are condenser adjustments preferred over the use of light intensity control?
Why are condenser adjustments generally preferred over the use of light intensity control? Answer: unlike the voltage control, condenser adjustments will increase illumination without affecting the bulb life.
What are the two things that can be done to improve contrast?
Contrast may be improved by placing suitable apertures or filters within the optical path, either in the illuminating system alone (dark ground or Rheinberg illumination), or in conjugate planes in the imaging system (e.g. for phase contrast, differential interference contrast or polarised light microscopy).
What is the condenser adjustment knob on a microscope?
Condenser Focusing Knob – This control is used to precisely adjust the vertical height of the condenser. Condenser Lens – This lens system is located immediately under the stage and focuses the light on the specimen.
How do you adjust a condenser lens?
When installing the microscope condenser, rotate the coarse focus knob (1) to move the stage to its highest position. Most compound light microscopes have a small knob (2) to raise and lower the condenser holder. Lower this holder so the condenser can slide into the holder below the stage.
What is a condenser do?
The purpose of the condenser is to receive the high-pressure gas from the compressor and convert this gas to a liquid. It does it by heat transfer, or the principle that heat will always move from a warmer to a cooler substance.
How should the condenser and diaphragm be adjusted for viewing?
How should the condenser and diaphragm be adjusted for optimum viewing? Condenser is kept at highest point, just below stage. Diaphragm varies based on how much light is needed.
How can you regulate the diaphragm?
The size of the field diaphragm is controlled by rotating a knurled ring which is concentric with it. The field diaphragm controls the area of illumination. Locate the field diaphragm and its knurled ring. The magnification of an image is primarily controlled by the objectives which are housed in a rotating nose piece.
Why would you adjust the fine adjustment knob?
FINE ADJUSTMENT KNOB — A slow but precise control used to fine focus the image when viewing at the higher magnifications.
What happens to the light intensity as you adjust the diaphragm?
What happens to the light intensity as you adjust the diaphragm? As you open the diaphragm its widest the most light is able to enter because it is open allowing all of the light to come in.
What position should the condenser be in?
Generally the condenser is used in its highest position or just slightly lower. A lever projects from the condenser and it is used to vary the opening of the condenser (or iris) diaphragm. For work with the scanning (4x) and low-power (10x) objectives, the condenser diaphragm should be wide open.
Which way do you need to turn the condenser to increase contrast?
With the condenser in place, focused and centred, the iris should be closed down so that it occupies the outer 20% or so of the field. This increases the contrast, making observation easier.
Does increasing magnification increase contrast?
Increasing magnifcation does not increase the contrast between an extended object and the surrounding sky. In fact, contrast is constant in all apertures at all magnifications.
How can you improve contrast when viewing a microorganism?
To increase contrast, the technician inserts an opaque light stop above the illuminator. The resulting darkfield image clearly shows that the bacteria cells are spherical and grouped in clusters, like grapes.
What is the function of the condenser on a microscope quizlet?
The purpose of the condenser lens is to focus the light onto the specimen. Used to vary the intensity and size of the cone of light that is projected upward into the slide.
Where is the condenser focus knob?
7. CONDENSER DIAPHRAGM ADJUSTMENT. a. USING THE CONDENSER FOCUS ADJUSTMENT KNOB THAT IS LOCATED ON THE LEFT SIDE OF YOUR MICROSCOPE JUST BELOW THE STAGE, MOVE THE CONDENSER UP TOWARD THE STAGE AS FAR AS IT WILL GO.
How do adjustments to the condenser iris affect visibility of each specimen?
In light microscopy the iris diaphragm controls the size of the opening between the specimen and condenser, through which light passes. Closing the iris diaphragm will reduce the amount of illumination of the specimen but increases the amount of contrast.Narrower widths provide greater contrast but also less light.
How do you adjust the condenser aperture diaphragm of the compound microscope?
The condenser aperture diaphragm can be controlled with a small horizontal lever (top). Left and right are the condenser centering screws. They are needed for adjusting Koehler illumination. Behind the left centering screw you can see the condenser focus knob.
Why do we need to adjust the iris diaphragm and condenser to control light intensity in the microscope?
Appropriate use of the condenser, which on most microscopes includes an iris diaphragm, is essential in the quest for a perfect image.On the other hand, the condenser should be lowered when using the scanning and low power lenses because the apertures are much larger, and too much light can be blinding.
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