Method for adjusting transfer voltage controls based on environmental conditions to improve print quality in a direct transfer image forming device

The present application is directed to methods of controlling the transfer voltage in a transfer nip formed between the photoconductive member and the transfer member. The methods offset the effects of large transfer current spikes caused when a media sheet enters and exits the transfer nip and account for temperature and humidity operating parameters using wet-bulb temperature measurements to adjust the transfer voltage. The control may include either ramping up or ramping down the transfer voltage. The ramped transfer voltage may include a series of alternating positive and negative steps that generally trend to ramp up or down. The size of the steps may further be adjusted to provide a smooth transition.