How often must the gauge be calibrated per FDOT?

• A. Annually (FDOT) or when needed
• B. Daily
• C. Weekly
• D. Monthly

Answer: (A)

Regular calibration keeps measurement readings trustworthy. For the FDOT, the gauge used to check field density is calibrated on an annual basis, and you also recalibrate whenever there’s a reason to doubt its accuracy—such as after a drop, after servicing, or if test results don’t align with expectations. This approach reflects that instrument drift is typically gradual, so an annual check reliably maintains accuracy without unnecessary interruptions. Daily or weekly calibration isn’t required because it’s more than what’s needed to ensure correct readings, and monthly isn’t the FDOT standard. The “when needed” clause covers situations where quick verification or adjustment becomes necessary due to suspect readings or changes in conditions.