Model Series FR. Radon diffuses into a counting chamber where the daughter recoils are concentrated by electrostatic attraction and deposited adjacent to a TLD or GM tube. FR-32 uses the TLD and FR-42 uses a GM tube. TLD needs to be sent to the lab for analysis readout.

• A one-week exposure gives a lower limit of detection of 0.03 pCi/l of Radon.
• Longer exposure gives greater sensitivity.

• No pump is necessary.
• Maintenance service:
• Replace the battery per schedule recommended in the user’s manual.
• Replace the indicating drying agent as needed (usually 2-8 weeks, depending on weather).

The FR-42 may be read in a few minutes.

It is the same instrument as the FR-32 but has a miniature Thin-Window GM tube and an internal scaler type display.