PerkinElmer Wallac 1420, Руководство пользователя

Страница: 79 / 171

Tools menu
77
Emission aperture
In front of the photomultiplier tube there is a 4-position aperture slide, which has three
different apertures and a shutter position.
The normal aperture is circular with a diameter of about 4 mm and it is used for factory set
labels.
The small aperture is circular but only 1 mm in diameter. This allows you to shift the
dynamic range of the emission signal for a particular user selected label which may
otherwise exceed the linear range of the instrument. This aperture is used for the top
fluorometry factory-set labels.
There is also a large circular aperture 5 mm in diameter.
The shutter is used at all times when no measurement is occurring to prevent stray light
getting to the photomultiplier tube.
Counter position
The counter position can be selected to be Top or Bottom .
Counting time
This parameter determines how long the excitation continues.
Second measurement parameters
In the case where you want to make measurements with two filters and/or two different
energies, you can set these parameters in this field. Click the check box
Second
measurement to activate them.
There are three of them: CW-Lamp energy , CW-Lamp Filter and Emission Filter. See the
corresponding sections for the first measurement for more details. When you select one of
more of these parameters two measurements are made, the first with the normal settings and
the second with these new settings. The change is automatic.