The Western Electric RA-330 and RA-331
Sound Level Meters Instruction Bulletin No. 1069
This Instruction Bulletin is available as a PDF for downloading in two resolutions, both of which are formatted for 8½ × 11 inches. The high-resolution version is best if you intend to print the book with sharp detail. Download links are at the bottom of this page. Here is what you will get:
Download the 19 MB high-rez Instruction Bulletin.
Download the 824 KB low-rez Instruction Bulletin.
High-resolution version is best for printing.