To explore the effect of temperature and humidity on optical resolution of portable endoscopy.

Measure the maximum resolution of line pairs per millimeter [r(d)] of the portable endoscopy with resolution card fulfilling national standard JB/T 9328-1999. Evaluate the r(d) under temperature -10、-5、0、5、10、15、20、25、30、35、40、45、50℃ and relative humidity 10、20、30、40、50、60、70、80、90%.

There was a tendency of decrease of r(d) at temperature under 0℃ or above 45℃ and also at humidity above 80%. The decrease was more obvious at cold moist environment, and less obvious at dry cold or dry hot environment. The endoscope maintains normal r(d) at temperature from 5 to 40℃ and relative humidity from 10% to 60%.

The portable endoscope has favorable resolution under a wide range of temperature and humidity.