User manual

4-16 VITEK

2 Instrument User Manual

510731-10EN1

Instrument Hardware Components VITEK

2 Instrument

Optics

The VITEK

2 instrument performs its identification and susceptibility

analyses by continually monitoring the growth and activity of organisms

inside the wells of the test cards. The optics system performs this function.

Transmittance Optics

The transmittance optics (1, Figure 4-10) use visible light to directly measure

organism growth. These optics are based on an initial light reading of a well

before significant growth has begun. Light transmittance samplings of the

same well every 15 minutes measure organism growth by how much light is

prevented from going through the well.

Figure 4-10: Optics

The optics use light emitting diodes (LEDs) that produce light at the

appropriate wavelengths, and silicon photodetectors to capture the

transmitted light. The system is self-calibrating.

Note: The optics should be cleaned periodically. See Cleaning Optics (Normal

Maintenance) on page 7-26.

Card Ejection

The card ejection function permanently removes test cards from the carousel

after their testing is completed. The mechanism that performs this function is

the same drive belt system that moves the test cards through the reader.

Instead of returning to the carousel, an ejected test card continues on to the

Waste Collection Station.

The amount of time that cards are held before being ejected automatically

from the carousel is set by an option in the System Configuration screen at

the workstation computer. Cards can also be ejected at any time using a

manual ejection function.