This Tiltmeter from the company PNI and the sensor is the fieldforce-tcm. All information is copied from the homepage of the company.

box, usb-rs232 converter, usb-plug + cap, sensor

https://github.com/mkoval/FieldforceTCM

http://www.pnicorp.com/products/fieldforce-tcm

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=18070

http://answers.ros.org/question/10546/pni-digital-compass-driver/#16791