A UV spectrophotometer's spare parts include the light source, monochromator (wavelength selector), sample compartment (cuvette holder), detector, and signal display system.

 A UV spectrophotometer's spare parts include the light source, monochromator (wavelength selector), sample compartment (cuvette holder), detector, and signal display system. 

Here's a more detailed breakdown:

Light Source:

This provides the UV and visible light needed for the measurement. Common types include: 

Tungsten-halogen lamp: For visible and near-UV light. 

D2 lamp (deuterium lamp): For UV light. 

Monochromator:

This selects the desired wavelength of light. It can be based on: 

Diffraction gratings: These separate light into different wavelengths. 

Filters: Absorption, interference, or cutoff filters can be used to select specific wavelengths. 

Sample Compartment (Cuvette Holder):

This holds the sample for analysis. 

Cuvettes: These are the small, optical containers used to hold the sample solution. 

Detector:

This converts the light signal into an electrical signal. Common types include: 

Photomultiplier tube (PMT): Detects very weak light signals. 

Photodiode: Converts light into an electrical current. 

Signal Display System:

This amplifies and displays the signal from the detector.