Topcon CT-80 non-contact Tonometer
Defect: Calibration issues, or measurements (IOP) isn’t right or consistent
The nozzle is blocked my dirt or debris OR voltage inconsistencies are causing inaccurate sensor feedback.
Clean the internal nozzle by using a very thin q-tip or other swab. You may also attempt blowing compressed air through the nozzle (softly). If the problem persists, the unit will require service
If above solution does not resolve defect, the device will most likely require service or repair.