How is calibration of the applanation tonometer checked?

The calibration of the applanation tonometer is checked by using a measured weight attached to the tonometer balancing arm. This process ensures that the tonometer provides accurate intraocular pressure readings. During calibration, a specific weight is applied; this weight reflects the pressure that the tonometer measures, allowing for precise adjustment of the instrument's readings. By doing so, practitioners can confirm that the tonometer is functioning correctly and provide reliable measurements of eye pressure, which is crucial for diagnosing and managing conditions like glaucoma.

Other methods, such as using a laser adjustment tool or manually adjusting the pressure gauge, are not standard practices for checking the calibration of an applanation tonometer. While comparing against a standard tonometer might seem viable, the direct method with a measured weight ensures accuracy through a physical check rather than relying on another device's calibration.