Standard rectangular cells with stopper (Type 21)

Product / Spectroscopy

Type 21 cells are identical to Type 1 except that a block with a ground hole to receive a PTFE stopper is fused to the top instead of an open top, giving a more suitable seal for volatile liquids. Cells with a path length greater than 20 mm are supplied with two stoppers. Unless specifically designed otherwise, all cells are assembled by fully fused construction without intermediate adhesives and can generally be used with pressure differentials of up to three atmospheres. Standard window thickness is 1.25 mm and the standard path length tolerance is ±0.01 mm (catalog general specifications).

Product group: UV/VIS and fluorometer cells
Brand: Starna Scientific

Manufacturer website

Source: manufacturer website (opens in a new tab) · Image: manufacturer website

Order codes and options

26 codes

Standard rectangular cells with stopper (Type 21) order codes and properties
Code	Window material	Path length	Nominal volume
21-G-1	Optical glass (334-2500 nm)	1 mm	0.4 mL
21-G-2	Optical glass (334-2500 nm)	2 mm	0.7 mL
21-G-5	Optical glass (334-2500 nm)	5 mm	1.7 mL
21-G-10	Optical glass (334-2500 nm)	10 mm	3.5 mL
21-G-20	Optical glass (334-2500 nm)	20 mm	7 mL
21-G-40	Optical glass (334-2500 nm)	40 mm	14 mL
21-G-50	Optical glass (334-2500 nm)	50 mm	17.5 mL
21-G-100	Optical glass (334-2500 nm)	100 mm	35 mL
21-SOG-10	Special optical glass (320-2500 nm)	10 mm	3.5 mL
21-Q-1	Spectrosil quartz (far UV) (170-2700 nm)	1 mm	0.4 mL
21-Q-2	Spectrosil quartz (far UV) (170-2700 nm)	2 mm	0.7 mL
21-Q-5	Spectrosil quartz (far UV) (170-2700 nm)	5 mm	1.7 mL
21-Q-10	Spectrosil quartz (far UV) (170-2700 nm)	10 mm	3.5 mL
21N-Q-10	Spectrosil quartz (far UV) (170-2700 nm)	10 mm	3 mL
21-Q-20	Spectrosil quartz (far UV) (170-2700 nm)	20 mm	7 mL
21-Q-40	Spectrosil quartz (far UV) (170-2700 nm)	40 mm	14 mL
21-Q-50	Spectrosil quartz (far UV) (170-2700 nm)	50 mm	17.5 mL
21-Q-100	Spectrosil quartz (far UV) (170-2700 nm)	100 mm	35 mL
21-I-1	Infrasil quartz (near IR) (220-3800 nm)	1 mm	0.4 mL
21-I-2	Infrasil quartz (near IR) (220-3800 nm)	2 mm	0.7 mL
21-I-5	Infrasil quartz (near IR) (220-3800 nm)	5 mm	1.7 mL
21-I-10	Infrasil quartz (near IR) (220-3800 nm)	10 mm	3.5 mL
21-I-20	Infrasil quartz (near IR) (220-3800 nm)	20 mm	7 mL
21-I-40	Infrasil quartz (near IR) (220-3800 nm)	40 mm	14 mL
21-I-50	Infrasil quartz (near IR) (220-3800 nm)	50 mm	17.5 mL
21-I-100	Infrasil quartz (near IR) (220-3800 nm)	100 mm	35 mL

Technical specifications

Standard rectangular cells with stopper (Type 21) technical specifications
Window materials	Optical glass, Special optical glass, Spectrosil quartz, Infrasil quartz
Path length range (mm)	1 - 100 mm
Nominal volume range (mL)	0.4 - 35
Number of variants	26

Source: starnacells.com (opens in a new tab) · Starna Cells 2026 Catalog, p. 5 (dimension table) · starnacells.com (opens in a new tab) · starnacells.com product type page. Values come from the manufacturer and are confirmed at the quotation stage.