# High Pressure Optical Cell Design Notes

## last updated 20190402

## Specifications

### essential

1. path length: 1 cm, <5% expansion @ SWP

2. beam height above baseplate: 34 mm*

*subject to revision by optical measurement -20190214

3. cuvette dimensions: 13 mm wide x 13 mm deep x 50 mm high (incl Teflon plug)

4. cuvette clearance: *as close as possible to 1 mm each side* *

*Cuvette should seat firmly in a shallow 13 x 13 mm recess at bottom of cavity.
2 inline windows should be as near to 1 mm from sample as possible.
3rd side window can be set further away as needed.

5. SWP: 9000 PSI

6. number of windows: 3

7. quartz window part dimensions: 8.5 mm thick x 19 mm dia.

8. window aperture: 10 mm dia.

9. access port: on top, diameter sufficient to remove/replace internal cuvette
using forceps. Closure should be installable in under 20 s and ideally involve
no loose hardware besides the cap and the pressure cell.

10. temperature control: 2-30˚C +/- 0.2˚C

11. temperature control plumbing spec:

Either 1/8" FNPT (tapered), to meet McMaster PN 4406T18

or 1/8" NPSM (straight w/gasket)

12. spectral range: UV/VIS (240-2000 nm)

13. mount: to fit Shimadzu RF-5301 with _custom polarizers_.*
Allowable footprint: 60 mm wide x 60 mm deep x 135 mm high

*Edmund Optics makes a micrometer-driven polarizer mount (stock #55-011)
that is 20.5 mm thick, allowing for the 60 x 60 mm cell footprint.

14. Pressure inlet specification: Valco standard 10-32 coned chromatography
fitting, female. See dims in Drawings folder.

Also, a [guide to variation in coned fitting standards](https://www.idex-hs.com/literature-tools/educational-materials/fittings-primer/):

Valco is a good manufacturer to go by.

### optional

1. Recess on top to catch and ideally drain overflow water.

2. mount: to fit Shimadzu UV-1601. 
Allowable footprint: same as Shimadzu RF-5301

## Notes

1.	ISS offers a 3-window cell that is overspecified for pressure and too large
for this application. It accommodates a round or square cuvette sealed with a Teflon plug.
http://www.iss.com/fluorescence/components/hpcell_system.html

2. Quartz windows for that cell are available separately, $160/ea (see quote for cell). They are 19 mm diameter, 8.5 mm thick; designed to provide a 10 mm aperture (see email from Beniamino Barbieri @ ISS.

3. [Here is a work-in-progress scale sketch](https://cad.onshape.com/documents/469bf1d505c7c4ef4e77fe10/w/c7b2f301d190eae42597c511/e/58fca7b84d4f4066138ca32d) of the (non-pressurizable) cuvette holder presently mounted in the RF-1501.