Thank you for your question. Delta Faucet model # 538T-SS-DST is equipped with touch free and a hands free mode. The proximity cannot be adjusted and is 3 inches from the spout. If someone soaping their hands removes their hands from the zone, the water will turn off.
If you would like to de-activate the hands-free mode, please follow these instructions:
1) Tap the spout 6 times within 4 seconds.
2) the LED indicator light will flash red/blue.
3) Tap the spout an additional 6 times within 4 seconds of the flashing red/blue LED indicator light.
4) The LED indicator light will flash red/blue a second time to indicate the hands-free mode has been de-activated.
5) The tapping sequence can be done with the handle in the ON or OFF position.