What Are Tiltmeters & Where Are They Used?
Have you ever wondered how do geologists get to know if the volcano is about to erupt or not or whether a building is about to fall or not? Well, all of this is measured using a geotechnical monitoring instrument known as tiltmeters.
Tiltmeters are a type of inclinometer that continuously monitor even the minor rotation, deflection, & deformation of retaining walls, diaphragms, volcanoes, dams, landslides etc. Beam Sensor, on the other hand, is similar to an El tiltmeter, designed to monitor differential movement and tilting of structures.
Here we will explain more about tiltmeters and beam sensors along with their different types and how are they used in the field of geotechnical monitoring.
What Are the Different Types of Tiltmeters?
Encardio-Rite deals with some of the most reliable, portable, low-cost, robust, and precisely-made tiltmeter sensors. The varied Models of tiltmeter include:
- EL Tiltmeter & EL Beam Sensor
- Portable Tiltmeter
- Uniaxial/Biaxial Tiltmeter without SDI-12 Interface
- Uniaxial/Biaxial Tiltmeter with SDI-12 Interface
- Box-type Tiltmeter with SDI-12 Interface
- MEMS Beam Sensor
- Box-type tiltmeter with MEMS Beam Sensor
- Tiltmeter with automatic data logger
- Wireless Tiltmeter
- Wireless Triaxial Tiltmeter
Let us now discuss all the types of tiltmeters in detail with their construction, as well as operating principles.
EL Tiltmeter & EL Beam Sensor
The EL tiltmeters contain an electrolytic tilt sensor housed in a compact, rugged, and weatherproof enclosure. Encardio-rite’s Model EAN-31EL EL tilt sensor is designed for measuring very small tilts, of the order of half a degree, with a high resolution.
It is used to monitor rotation and deflection of structures such as buildings, retaining walls etc. in a vertical plane. These are normally used as a stand-alone unit for measuring tilt.
There are two ways in which the tilt sensor is used to measure the amount of tilt. One of them is by directly attaching it to the structure using suitable mounting brackets or fixed to horizontal or vertical beams.
The Model EAN-31EL-B beam sensor consists of the Model EAN-30EL, electrolytic tilt sensor mounted on a beam of fixed gage length and suitable mounting hardware for securing the beams to the structure.
The beam sensors are commonly linked together to give a differential displacement profile. An array of linked beam sensors allows the vertical settlement profile along the array line to be determined.
The Model EAN-41EL-B tiltmeter is designed to monitor inclination and vertical rotation of structures. It is a high-resolution tilt sensor and rugged in construction. The electrolytic tiltmeter is contained inside a 1, 2 or 3 m long beam. The Model EDI-53ELV read-out logger is used to read voltage output from the sensor. The output can also be monitored or recorded at any remote location by an automatic data acquisition system or automatic data loggers.
Portable Tiltmeter
The Encardio-Rite Model EAN-70M portable Tiltmeter is designed for monitoring changes in the inclination of any structure. It is a high-resolution tilt sensor using the inclinometer probes proven technology to function.
This tiltmeter is ruggedly built and possesses excellent temperature stability. Tilt changes in structures may occur due to construction activities such as excavation, tunnelling and de-watering that affects the ground supporting the structure.
The loading of a structure, such as loading of a dam during impoundment, loading of a diaphragm wall during excavation or loading of a bridge deck due to wind and traffic can also cause changes in tilt. Data from Model EAN-70M tiltmeter provides early warning of threatening deformation, allowing time for corrective action to be taken.
Uniaxial/Biaxial Tiltmeter without SDI-12 Interface
The Encardio-Rite Model EAN-90M/92M tiltmeter is suitable for monitoring inclination and vertical rotation in structures. It is a high-resolution tiltmeter, sturdy in construction and with superior temperature stability.
The Model EAN-90M tiltmeter consists of a primary sensor, mounted inside stainless steel housing. The sensor output is 4 V nominal at ± 15°. This output can be carried over long distances without any signal degradation.
The sensor renders a comparatively low-cost system which offers an excellent resolution, long term stability and low thermal sensitivity. The tiltmeter (uniaxial and biaxial) is installed on a vertical or horizontal surface through an adjustable bracket and expandable anchor. Movement of the structure causes a shift in the tilt of the tiltmeter, which results in a difference in the output of the sensor.
Measurements can be made on horizontal or vertical surfaces. Subsequent sets of readings explain how the structure is behaving and indicate permanent deformations as time progresses.
Uniaxial/Biaxial Tiltmeter with SDI-12 Interface
The Model EAM-92M tiltmeter is available with SDI-12 interface such that all sensors can be connected through a single bus cable to the data logger.
The SDI-12 bus cable from different tilt sensors can also be connected to the same data logger. Although tiltmeter with SDI12 interface is a bit costlier, the savings in cable costs and the [Continue Reading...]