·	Inbuilt Level Zeroing Indicator

·	Level Status LED’s

·	Microprocessor controlled for increased

accuracy

·	Analogue Output for local measurement

·	433 and 434 MHz Operation

·	Solutions to 512 Sensor Channels

·	250 m Line Of Sight Range

·	32 Channel Receiver Unit - Model LSI-R102

·	Directly Compatible to all Keynes Data

Acquisition Systems

·	Battery Life - 1 to 10 years

·	Solar Power Option available

·	Automatic Fault Detection System

·	Resolution to 0.003 Deg

Introduction

The Settlement/Tilt sensor is based around the Slope Instrumentation range of EL Sensors attached to a rigid metal beam with adjustable mounting attachments. The tilt sensor is a precision bubble device that varies in resistance depending upon its angle of tilt and is used as part of bridge circuit. As the sensor tilt angle varies the output of the bridge changes level in proportion to movement. The rigid metal beams are typically 1 to 2 metres in length and can be deployed in both the horizontal and vertical planes.

The signal conditioning for the sensor is undertaken by the the Keynes Controls LSI-T102 module which incorporates sensor signal conditioning, analogue signal output, zero level adjustment indicator and UHF transmitter for wireless operations into a single device. The T/S-102 level is adjusted using the Thumb Wheel Leveling Screws.

Operations

Once the the bar is mounted to the surface to be monitored, the radio antenna attached or the unit connected to a local logging device then upon activating the level status button the sensor will indicate which direction the level sensor is to be adjusted to zero the device. Once both level status LEDs are illuminated the tilt sensor is perfectly level. After a timeout period of 1 minute the sensor status LEDs will be powered off to minimise power. The zero level can be further adjusted if necessary by simply reactivating the Level Status button. The analogue output channels on the LSI-R102 receiver module only changes level when there is a change in the sensor signal levels even though the sensor itself may be sleep mode prior to making a fresh reading.

Channel Selection

Each LSI-T102 module contains 8 DIP switches for selecting the channel to be used. Each sensor must have a unique channel number assigned when used with the radio interface.

The LSI-R102 receiver module contains 5 channel selection DIP switches that are used to select the sensors in blocks of 32 channels. The channel selection on the sensor also defines which output on the receiver is used to provide the signal to the data logger or display unit.

LSI-R102 Receiver Module

The Keynes Controls LSI-R102 receiver module detects signals from the settlement/tilt sensors and translates the sensor signals to analogue output proportional to the tilt angle. Each receiver module supports up to 32 individual sensors. Multiple receiver units can work together and systems up to 512 channels can be seamlessly integrated. The output of the LSI-R102 can be directly connected to all Keynes data loggers & acquisition systems.

Fault Detection System

The LSI-R102 receiver polls for the sensor input signals every 10 minutes and any sensor that does not respond causes the corresponding analogue output on receiver to drop to 0V. This level change can be used to trigger alarm messages to an operator. The alarm will automatically clear when the sensor signal is returned to operation. Alarm messages can be sent to users locally on a LAN and remotely across the Internet when operations are combined with Keynes Logger Units.