Ibrahim, TJ O'Hanlon

There was question about where the prism position was with respect to the nominal position (known to be 2.6775mm from the cetner line as figure 1 shows).

As it turns out, measuring from the scribe line of the center of the dummy test mass, yields an "dummy mass upside down" answer that has confused us (LLO Measurement). However, using the scribe on the glued tooling that we used to determine the secondary prism location resulted in the correct value ~2.73mm. While all these are rough measurements, I wanted to check if LLO's upside-down metal-prism version is equivalent to LHO's scribe-on-prism tooling glued-on version. For the LLO comparison, I used the metal prism build dimensions from D1900580. According to a scale-comparison (using line lengths ratios), they are at least comparable (Figure 2).

TJ agrees that the the scribe line I'm using, which was on D2400027 (also screenshotted below) and says "our prisms are in the same place but you are measuring off of the scribe line off the D24000247 while I am looking at the center round mass. The center round mass scribleline would match with d24000247 if it wasn't flipped".

Meaning LHO and LLO prisms are in the same spots but that the dummy scribe line is not to be trusted. That spot also matches (with at least +-1 mm error until measured more accurately) the 2.67mm nominal value.

I've attached some pictures of the measurement.