There are three output types we can offer for our Tiltbeam:
- +/- 5 Volts
Voltage and 4-20mA are both considered to be an Analogue signal which may be preferable to those that want to use their own Datalogger or simple readout device. Voltage is limited by not being able to achieve long cable lengths however 4-20mA can pick up the benefits in this respect. So if an Analogue signal is preferable and you need a long cable length (>70m), 4-20mA would be the better choice.
Should there be a situation where you require a number of Tilt Sensors in a string to achieve a profile, then RS485 would be the preferable choice. The benefit of RS485 signal is that the Tiltbeams can be daisy chained, minimising the amount of cables running to a datalogger. These can also be read using a handheld Field PC or more often a GeoLogger with an RS485-RS232 Interface. Each Tiltbeam is communicated with using the serial number assigned to it and sends 1 or 2 Tilt value depending on Uniaxial or Biaxial (usually Sin angle) and Temperature reading.
The design of Geosense Tiltbeams is dependent on the output of the sensor. If they have an analogue output, due to the design on the PCB board this is simply a standard In-Place Tiltmeter mounted on an Aluminium beam of a desired length. However if the output is RS485 digital then the board is small enough to fit inside the 1 ½” x 1 ½” box section beam becoming a discreet sensor. The cabling is then run from end to end with an EMC compliant cable gland protruding.
The following sub-titles refer to what feature is most important when deciding on the type of Tiltbeam to use:
Analogue Tiltbeams are supplied with the Tiltmeter mounted on the beam in an IP66 enclosure meaning they are protected against strong jets of water (i.e. heavy rain). If there is any chance at all of the Tiltbeam becoming submersed, a Submersible Tiltmeter (IP68 to 200m) would then be mounted instead.
Isolated Data logging
If the monitoring points are accessible but few and far between and you also require data logging, the Tilt Logger would be ideal as this is mounted at your point of interest. This can then in turn be mounted to a beam of required length. It will record the Tilt measurements at the desired intervals at which point you can download the data as and when it is required using a Laptop or Windows operated handheld PC.
Multiple monitoring poinst in close proximity to each other
Digital Bus Tiltbeams would be the way forward here to allow you to connect each Tiltbeam in series and have only one cable sending the data from all Tiltbeams in that array. Saves a considerable amount of cable needed for the job.
Biaxial or Uniaxial
All Tiltbeams have the option of being supplied with Single or Dual axis Tilt boards however Biaxial is usually only required when the bema is mounted Vertically. Biaxial is slightly more expensive so depending on your application or measurement requirements, you are able to make a decision on which would be better suited and potentially save some cost where you can get by with Single Axis measurements. Biaxial for horizontal applications could also be of interest when you are also looking to measure twist within a tunnel for example when running a series of beams along the length of the measured section.
Standard range of beam lengths run from 1m to 3m of course you can mix and match the lengths to make up a certain distance which you require to monitor. 1m lengths could be employed for when you need to focus more closely on a particular section. The total length of the beam is measured from mounting each mounting centre where the mounting bolts would seat in. This is to ensure that when beams are mounted in a string that they make up the desired total length required to monitor i.e. a 30m section would require 10no. 3m Beams.
Tiltmeter or Tilt Beam
Generally this question is only applied when trying to measure Tilt in a vertical plane. It depends on whether you can comfortably assume that the structure you are measuring will move as a uniform entity. If this can be assumed then a Tiltmeter will suffice. However, as in most cases, this cannot be assumed and this is where a Tilt Beam would be superior in providing you with a better understanding of how that structure is moving. For example, if you are measuring the Tilt on a church steeple with a 3m Tilt Beam, you cannot assume that the displacement from the vertical plane you are measuring can be applied to the entire height of the structure. Therefore it would be preferable to place numerous Tiltbeams to span the full height of the structure. This way it can provide a useful profile of what is happening to the building as a whole.
Orientation of Tiltbeam:
Geosense Tiltbeams have a standard measuring range of +/- 15°. This 30° range can be adjusted to suit the orientation at which the Tiltbeam would need to be mounted to ensure you are making the most of the measuring range for that application. Generally, a Tiltbeam is either mounted Horizontally or Vertically. A suitable mounting bracket would then be supplied depending on this detail. Each sensor is supplied with a sticker showing the measurement range it has been calibrated for.
Sometimes the occasion calls for a Tiltbeam needing to be mounted on an angle for example the curve of a tunnel. Should this be required Geosense can supply the beams with an adjustable swivel mounting end to allow you to achieve the angle needed but keep within the measurement range of the sensor
Geosense Tiltbeams are manufactured to meet the Electromagnetic Compatibility Directive 2004/108/EC. To comply with this directive, special braided cable needs to be used which ensures the EMC protection throughout the cable route. If the cable is to be spliced, a special splice kit is to be supplied to ensure the EMC compliance is continued. If he cable terminates in a datalogger, Geosense supply EMC compliant cable glands which crimp on to the braid of the cable. All RS485 digital output Tiltbeams and uniaxial Analogue Tiltbeams require a twisted pair braided cable. Biaxial Analogue Tiltbeams require 3 twisted pair braided cable to be able to send the signal from the extra measuring axis.