What causes the Astro TOC/1950+ to read low?
Astro TOC/1950+ Reading Low
Low readings stem from issues on the right side of the analyzer. 1. Persulfate bubbles or weak persulfate. If insufficient persulfate is mixed with the sample and carrier gas then complete oxidation will not take place. 2. Weak UV lamp or lamp not lit - the lamps should be replaced once a year. Slide a piece of paper underneath the UV manifold and check for a faint purple glow as this indicates the lamps are lit.