Integrated health monitoring &

Sensor applications

Presented By: Nimesh Sharma

Optical sensorsfor groundwater level monitoring

Contents Introduction to Integrated health monitoring & sensor

applications.

What are Optical sensors?

Why do we need groundwater level monitoring?

Application of Optical sensors for groundwater level monitoring to:

(a) Physics(b) Electrical Engineering

(c) Mathematics(d) Civil Engineering

Integrated health monitoring &

Sensor applicationsRole of Sensors in Structural Health Monitoring (SHM) process :

High-rise buildings, arenas/stadiums and historical monuments are complex structures.They are comprised of multiple elements and components that interact with one another and become stressed when exposed to external phenomena.

The development of sensors characterized by increasing performances and of wireless sensors networks, develop faster than algorithms to better understand the behavior of structures under dynamic loads, seismic protection, observation, in real or near real-time, of the structural response.

Benefits of Integrated Building Health Monitoring Solutions 1 - Integrated solutions 2 - Increased safety of people, nature and property 3 - Extend the lifetime of aging buildings 4 - Reduced insurance and maintenance costs 5 - Quick access to building safety information after a major event 

Primary sensing approaches

• Conventional strain gauges

• Optic systems (strain and acceleration)

• Conventional accelerometers(strain, impedance, actuation)

Optical sensorsfor

groundwater level monitoring

What are Optical SensorsAn optical sensor is a device that can measure the intensity of electromagnetic waves in a wavelength range between UV light and near infra red. Usually, the optical sensor is part of a larger system integrating a measuring device, a source of light and the sensor itself.

For example :• Lamps that turn on automatically in response to darkness• Position sensors that activate when an object interrupts a

light beam• Flash detection, to synchronize one photographic flash to

another• Photoelectric sensors that detect the distance, absence, or

presence of an object

Groundwater monitoring is important for three main reasons.

1. to ensure that the supply of fresh water is not depleted by excessive abstraction or as a result of global warming

2. to check that water quality is not adversely affected by pollution or saltwater incursion

3. to monitor rising groundwater levels that could cause flooding or flush sources of pollution.

Why do we want to monitor groundwater?

Application of Optical Sensors

for Groundwater Level Monitoring

Physics Optical sensors work on principle of detection of light. The basic measurement device is the photodiode. For monitoring groundwater level they make use of position

sensors which determine depth of water level from surface.

This is generally done using an electrical trigger, which reacts to a change in the signal within the light sensor.

Electrical Engineering

These sensors convert the optical signals received by means of the electrical trigger into electrical signals.

The converted signals are interpreted by a measuring device.

These signals after interpretation are displayed on the screen/display.

Mathematics

The algorithm in the measuring device calculates the distance between surface and groundwater level using simple math.

Speed of source usedWater Level = Half the time taken for sensor to detect the reflected signal

Civil Engineering

Construction of the structure to support sensor

Digging up of ground and placing vent tubes for functioning of the sensor.

Maintenance of sensor apparatus internally and externally.

Working

algorithm

electrical signals