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UV-Vis Spectrophotometer vs Visible Spectrophotometer

2024-08-20
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UV-Vis Spectrophotometer vs Visible Spectrophotometer

Visible spectrophotometer and UV-visible spectrophotometer is the difference between the determination of different wavelength ranges, UV generally use hydrogen or deuterium lamps, the determination of the wavelength range of 180 ~ 350nm, visible generally use tungsten lamps, the determination of the wavelength range of 320 ~ 1,000nm. the so-called UV-visible spectrophotometer, that is, the instrument can be replaced with a new source of light, the ability to determine the peak of the absorption in the UV and the visible portion of the compounds.

It is normal to find that the absorbance is no longer displayed when it exceeds 2.

Absorbance is the negative logarithm of transmittance, and an absorbance of more than 2 means that the transmittance is less than 1 per cent, which is below the detection limit of the instrument, and is no longer displayed.

Whether you can use a spectrophotometer or not depends on the wavelength you are measuring.

Specifically divided into the following points:

the wavelength range is different: ultraviolet-visible spectrophotometer wavelength range is: 200nm-1000nm, of which 200nm-330nm calibrated for the ultraviolet spectrum, 330nm-800nm calibrated for the visible spectrum, 800nm-1000nm calibrated for the near-infrared spectrum. The visible spectrophotometer wavelength range is only in the visible spectral region of 330nm-800nm.

2) the light source is different: visible spectrophotometer light source is generally only tungsten lamps, while the UV-visible spectrophotometer is a tungsten lamp + deuterium lamp two light sources, but also more than the two light source lamp switching components. This is because the spectral range of tungsten lamps can be seen mainly in the near infrared, deuterium lamps are mainly in the ultraviolet end. It is also because the light source is not the same, ultraviolet-visible spectrophotometer also has a special deuterium lamp to provide deuterium lamp work deuterium lamp power supply.

3) the different optical devices: because the glass can absorb ultraviolet waves, and can be seen on the near infrared end of the better permeability, so some of the optical components of the visible spectrophotometer can be used in glass, while the UV-visible spectrophotometer can not be used in glass components, the general use of quartz optical components. At the same time for this reason, the choice of cuvette is also different, visible spectrophotometer can use glass cuvettes, while the UV-visible spectrophotometer generally use quartz cuvettes.

the receiver is different: due to the ultraviolet-visible spectrophotometer more ultraviolet waves, so the choice of the receiver is not the same. More sensitive response to the ultraviolet wave function, the price of such receivers than the visible spectrophotometer receiver is much more expensive.

the analysis of different substances: the majority of the analysis of the ultraviolet spectrum of organic matter, the majority of the analysis of the visible spectrum of inorganic matter, of course, is not absolute, just most of the absorption of organic matter sensitive point in the ultraviolet spectral region, the absorption of inorganic matter sensitive point in the visible spectral region.

Frequently Asked Questions about the two types of spectrophotometers

1.What is the difference between a visible spectrophotometer and a UV-visible spectrophotometer?

The difference between a visible spectrophotometer and a UV spectrophotometer is that the wavelength range of the measurement is different, generally the visible wavelength range is 400 ~ 1000nm, the UV wavelength range is 200 ~ 400nm. the so-called UV-visible spectrophotometer that is to say, the instrument can be replaced by changing the light source to form a UV and visible light area, able to determine absorption peaks in the ultraviolet and visible part of the compound. Generally, the wavelength of measurement is from 200 to 1000nm.

2.What are the key parameters of a UV spectrophotometer?

Selection of visible and UV-visible spectrophotometer concerned about the key indicators are three points: one is the wavelength range, the second is the wavelength accuracy, and the third is the stray light parameters. The choice of wavelength range is determined by the user’s experimental needs, the wider the wavelength range of the price of the more expensive; wavelength accuracy and stray light parameters of the lower the value of the performance is better.

3. Ultraviolet spectrophotometer double beam and single beam how to distinguish between

Where the optical path to put two cuvettes, one for the sample, one for the reference, each corresponding to a set of through the light window, is a double beam. Where there is only one cuvette bit, or where you can only find one set of through-light windows (so that you can rule out confusion about multi-cell attachments), there are two cases: 1) Quasi double beam. There is also a reference light all the way inside the instrument (unfortunately you can’t see it, and there is no way to put a reference cuvette), and there is usually a reference detector inside (mostly silicon photocells). 2) Pure single-beam, light from the inside out only one way (not counted before switching the light source mirror), only a cuvette position, of course, there is only a detector.

4.AELAB all kinds of uv/vis spectrophotometer as below for your reference.

Type	Style	Series	Model	Wavelength range	Bandwidth	Marks
UV VIS Spectrophotometer	Double beam	AE-S90-Series	AE-S90-MD	190-1100nm	0.5/1/2/4/5nm	with PCsoftware
			AE-S90-1D	190-1100nm	1nm	with PCsoftware
			AE-S90-2D	190-1100nm	1.8nm	with PCsoftware
	Single beam	AE-S80-Series	AE-S80-MS	190-1100nm	0.5/1/2/4/5nm	with PCsoftware
			AE-S80-1S	190-1100nm	1nm	with PCsoftware
			AE-S80-2S	190-1100nm	1.8nm	with PCsoftware
		AE-S70-Series	AE-S70-1U	190-1100nm	1.8nm
			AE-S70-1UPC	190-1100nm	1.8nm	with PCsoftware
			AE-S70-2U	190-1100nm	2nm
			AE-S70-2UPC	190-1100nm	2nm	with PCsoftware
		AE-S60-Series	AE-S60-2U	190-1100nm	2nm
			AE-S60-2UPC	190-1100nm	2nm	with PCsoftware
			AE-S60-4U	200-1000nm	4nm
			AE-S60-4UPC	200-1000nm	4nm	with PCsoftware
Visible Spectrophotometer	single beam	AE-S70 Series	AE-S70-2V	320-1100nm	2nm
		AE-S70 Series	AE-S70-2VPC	320-1100nm	2nm	with PC software
		AE-S60 Series	AE-S60-4V	325-1000nm	4nm
		AE-S60 Series	AE-S60-4VPC	325-1000nm	4nm	with PC software
		AE-S50 Series	AE-S50-4V	325-1000nm	4nm
		AE-S50 Series	AE-S50-4VPC	325-1000nm	4nm	with PC software
		AE-S30 Series	AE-S30-6V	330-1000nm	6nm
		AE-S30 Series	AE-S30-6VS	320-1000nm	6nm

Frequently Asked Questions

1What is the main difference between a visible spectrophotometer and a UV-Vis spectrophotometer?

The key difference is their wavelength ranges and light sources. A visible spectrophotometer measures wavelengths roughly from 320–1000 nm using a tungsten lamp, while a UV-Vis spectrophotometer covers a broader range from about 200–1000 nm by combining a deuterium lamp (for UV) and a tungsten lamp (for visible light).

2Why do UV-Vis spectrophotometers use quartz components instead of glass?

Quartz is used because glass absorbs ultraviolet light and is less transparent in that range, while quartz allows UV light to pass through efficiently. This is important for UV-Vis spectrophotometers that operate in the ultraviolet spectrum.

3What are the key performance parameters to consider when choosing a UV spectrophotometer?

The three main parameters are wavelength range (broader range increases cost), wavelength accuracy (lower error is better), and stray light levels (lower stray light improves measurement quality).

4How can you distinguish between a single-beam and a double-beam UV spectrophotometer?

A double-beam spectrophotometer has two cuvette holders—one for the sample and one for the reference—allowing simultaneous measurement. A single-beam spectrophotometer has only one cuvette holder and measures sample and reference sequentially.

5What types of samples are typically analyzed using UV versus visible spectrophotometers?

Organic compounds are usually analyzed in the ultraviolet range because they absorb UV light strongly, while inorganic compounds are often analyzed in the visible range due to their absorption characteristics.