Three Sigma 40 cells that read “Not published” in our table are published on Perry's own product page, and are now transcribed.
What we found
Perry Baromedical's Sigma 40 product page carries a table headed Technical Specifications with fourteen populated fields, including maximum operating pressure, weight, and width, length and height. Our comparison row for that chamber recorded maximum pressure and weight as “Not published” and recorded only the interior diameter under dimensions. Those three cells are now transcribed from the manufacturer's own table, in the manufacturer's own units.
| Field | Our row, read 28 August 2026 | Perry product page, read 31 August 2026 |
|---|---|---|
| Maximum operating pressure | Not published | 30 psi / 3 ATA (2.07 bar) |
| Weight | Not published | 2850 lbs. / 1293 Kg |
| External dimensions | Interior diameter 40.5 in; length and external dimensions not published | Width 46 in. / 1.168 meter; Length 105 in. / 2.667 meter; Height 68.75 in. / 1.746 meter |
| Internal dimensions | Interior diameter 40.5 in | Internal Diameter 40.5 in. / 1.029 meter; Internal Length 93 in. / 2.362 meter; Internal Volume 69.3 cu. Ft. / 1.962 cu. meter |
What we are not claiming
We cannot tell you that Perry added these figures between the two dates. We did not archive the page on 28 August, so we cannot distinguish a change on Perry's side from a miss on ours. The before column above is our record, not a dated observation of Perry's page in an earlier state, and it is labelled that way. Where our own extraction was at fault — the value column of Perry's table is right-aligned in a layout that a text-only read can drop — the honest description is that we got it wrong and have fixed it.
One figure still not published
Perry publishes no price for the Sigma 40, so that cell still reads “Not published” and will keep reading that way until Perry publishes one. The page also states that Perry systems “meet or exceed current requirements of ASME, PVHO-1, NFPA-99 Chapter 20” without naming an edition, which is the subject of a separate bulletin below.
What it means if you are buying
If you were filtering our table for hard-shell chambers at 3.0 ATA, the Sigma 40 was missing from that filter and now appears in it.
How this was verified
The Perry product page was fetched and its raw markup inspected on 31 August 2026, after a text-only extraction of the same URL on the same day returned the field labels without their values. Every figure above was taken from the markup of the specification table, not from a summary of it.
Sources
- Perry Baromedical — Sigma 40 product page, Technical Specifications tableSource read on 31 August 2026 · Values read from the page markup; a text-only extraction of the same URL dropped the value column.