In what situation is a speed measurement device considered calibrated?

A speed measurement device is considered calibrated when it is checked against a known speed standard. Calibration refers to the process of verifying a device's accuracy by comparing its measurements to established reference standards. This ensures that the device produces reliable and valid results.

When a speed measurement device is checked against a known speed standard, it allows for the identification of any discrepancies in the device's measurements. This process is crucial because accurate speed measurements are essential for law enforcement and other entities that rely on speed detection technology. If the device consistently measures accurately in comparison to the known standard, it confirms that the device remains in operational condition for its intended use.

The other situations listed—operating under different environmental conditions, after maintenance or repair, or only being used in a specific location—do not inherently qualify the device as calibrated in the same sense. While environmental conditions and location may affect the measurements taken, they do not directly verify the device’s accuracy. Maintenance or repair is important for ensuring functionality, but calibration specifically involves checking against a known standard to affirm precision.