Z Dimensions of Ultra Micro Volume Cuvettes

(List of 474 Instrument Data)

To determine the Z dimension of popular instrument models, please use our “Z dimension Finder with Instrument Models” at the end of this article.

How to define the “Z dimension” of a micro volume cuvette?

A spectrophotometer cuvette z dimensions is the length from the base of the cuvette to the center of the solution window (where the light passes).

The Z dimension is usually defined for ultra micro volume cuvettes or flow through cells, where there is a limited sample aperture.

For instance, Z dimension should be defined for the following types of cuvettes: 

How important is the Z dimension?

When using an ultra micro volume cuvette, it is important that your sample solution is placed in the middle of the instrument light beam. Otherwise, incorrect or noisy data reading will probably be taken. Any light source which does not pass through the solution should ideally be blocked (or masked) with a black wall. If the cuvette is not masked properly, the absorbance sensitivity to measurement might probably be decreased.

Why does the Z dimension differ from instrument to instrument (brands)?

Every instrument company is making engineering decisions to design and manufacture its instrument to make sure its performance is optimal. The length, width, height and adjustment of the light source in the spectrophotometer is based on the design taken on engineering to make sure that the instrument meets its released brochure specifications.

How can I find my instrument’s Z dimension?

For each commercial instrument, the correct Z dimension or center beam height should be described in the manual from to the manufacturer. 

You can also call the manufacturer to find out what the Z dimension of the instrument is. Things happen that even they can’t tell you! In this case, we have also compiled a list of 474 instruments and brands for finding the Z dimension (light beam height) of the most commonly used instruments below by the end of this article.

How can I find my instrument Z dimension by myself?

Many of the instruments have different Z dimensions, or the Z dimension can vary with respect to the alignment of the light source within the model. Therefore, it is useful to learn how to find out the Z dimension by oneself.

Check Z dimension by Method One

Check your instrument Z dimensions can be very simple. Follow these steps below:

1. Prepare a thick white card or paper sheet with size about 12 mm wide and 100 mm long.
2. Cut the first hole, about 3 mm (simply push a ballpoint pen through the card), in the center of the card and 8.5 mm from the bottom. And the second hole 15 mm from the other end of the card bottom.
3. Switch your spectrophotometer on in %T mode and set it to any relevant wavelength.
4. Put the prepared card inside the cell holder as if it’s a cuvette. Either the 8.5 mm or 15 mm end will transmit light and you’ll know the Z dimension of your instrument. 
5. If neither is correct then make up another piece of card with holes placed at different dimensions (20 mm or other sizes) and determine which one works optimally. Check our chart “Z dimension Finder with Instruments Models” for some suggestions.

Check Z dimension by Method Two

Alternatively, if the sample compartment can be accessed easily, there is a simpler way to measure the instrument Z dimension. 

1. Set the instrument at visible wavelength (e.g. 546 nm). 
2. Put a piece of white card in the sample compartment. 
3. Mark the card with a pencil where the light beam lines up.  

The Z dimension should be approximated by the distance from the bottom of the card to the mark.