High Resolution Tiltmeters

High resolution 1K - Platform Tiltmeter

• Resolution: better than 0.5 nrad
• Power consumption /sensor: < 30mW
• Height:  < 150mm 
• The first 6 sensors have been installed in Wettzell since early 2002

At the Geodetic Base Station Wettzell in SE Germany a large ring laser has been installed. Aimed at the high resolution observation of the rotation of the earth, it is necessary to monitor the tilt of the base of the system with extremly high accuracy. Commercially available borehole-tiltmeters have sufficient resolution - however, due to the large size of those instruments with a length of the order of 1m a borehole-tiltmeter could not be used.  Another constraint was a very low power consumption of the tilt sensors as any temperature change could interfere with the ring laser measurements.The tiltmeters developed for this purpose are operational since 2002. For online data please visit :http://www.wettzell.ifag.de/LKREISEL/GrossRing/view _tiltmeter.html

Tides of the solid earth :
first results at BFO (Black Forest Observatory:
first&second trace: East-West
third&fourth trace: North-South
first trace: LGM tiltmeter
second trace: Askania Borehole tiltmeter
third trace: LGM tiltmeter
fourth trace:Askania Borehole tiltmeter

2-Component-Sensor:
 Size: 150x150mm
 height 120mm
 weight appr. 1.5kg
 low power-  40mW
resolution : 1 nrad
integrated high resolution temperature sensor

resolution test : a 70nrad input signal is clearly resolved with high signal-to-noise ratio. The signal source was a person moving back and forth in a room the first floor of a buildding. The sensor was installed in the cellar below.

2-channel borehole tiltmeter module
resolution: appr. 1nrad
integrated high resolution temperature sensor
diameter 40mm
outside diameter of stainless steel
borehole tiltmeter case: 50mm

Download: Tiltmeter-Module Datasheet (.pdf, 31kB)