Different Sensors

Engineering Behind

How Lab in Your Pocket Works

Mobirise

From Sensor

The sensor detects the surrounding parameters and sends analogue signals to the microcontroller, embedded in the 3D printed box.

Mobirise

Through
Microcontroller

The microcontroller, playing the role as an agent, deciphers the signals received and constantly broadcasts the series of data with its Bluetooth module.

Mobirise

To App Interface

As a mobile device is paired with the microcontroller via Bluetooth, the Lab in Your Pocket app displays the data comprehensive to user. Data could furthermore be saved and analyzed.

Sensors

Latest Version
(Compatible with new LabXRA app)

數據記錄器

Data Logger

The data logger is specifically designed to collect and transmit data received from various connected sensors. It enables real-time monitoring of environmental changes and wirelessly transmits the collected information to a mobile application, allowing users to view and analyze data anytime, anywhere.

電流及電壓傳感器

Current & Voltage Sensor
(Requires use with Data Logger)

The current and voltage sensor is a device that integrates both current and voltage measurement functions, aimed at providing accurate power data monitoring. For current measurement, the sensor features a low internal resistance design to ensure the normal operation of the circuit is not affected. Meanwhile, for voltage measurement, the sensor relies on voltage division principle to accurately capture voltage variations.

氧及二氧化碳傳感器

O2 & CO2 Sensor
(Requires use with Data Logger)

The oxygen sensor operates based on an electrochemical mechanism, with the voltage output inside the sensor being proportional to the oxygen concentration. The carbon dioxide sensor uses a principle similar to that of the suspended particle sensor, with the "beam" used here being infrared light. It is well known that carbon dioxide is a greenhouse gas that efficiently absorbs infrared radiation.

光強傳感器

Light Sensor
(Requires use with Data Logger)

The light sensor is a device capable of measuring ambient light intensity, primarily based on the photoelectric effect. When light strikes the photosensitive component, it generates a photocurrent proportional to the intensity of the incident light. This photocurrent is received by the microprocessor and converted into values, providing accurate light intensity readings.

Weak Laser

Weak Laser
(Requires use with Data Logger)

The weak laser is a low-power output laser, which makes it safe for various experiments, particularly in optical reflection experiments. Its effectiveness is particularly notable when used in conjunction with a light sensor.

Sound Level Meter

Sound Level Meter
(Requires use with Data Logger)

The sound level meter is a device specifically designed to measure sound intensity, typically displaying measurement results in decibels (dB). Its operation is based on the effect of sound waves on an internal microphone, which converts sound into electrical signals. The internal processor then calculates and displays the corresponding sound intensity.

Old Version
(Compatible with new LabXRA app)

Gas Sensor

Gas Sensor

It comprises temperature and pressure sensors. The sensors determine temperature and pressure from the electrical output across a thermoresistor and a pressure-sensitive semi-conductor respectively in the circuit. This electrical output is converted into its corresponding temperature and pressure by the microcontroller.

Current Sensor

Current Sensor

It is straightforward for the microcontroller to read the analogue signals from the current sensor. The higher the current flowing through, the stronger is the signal received. It possesses very low internal resistance such that it does not divert much current from a series circuit.

Voltage Sensor

Voltage Sensor (version 2)

The working principles of voltage sensor are a bit complicated and varied from type to type. In general, there exists a voltage divider that allows high voltage measurement. The internal resistance is set high enough to not affect the equivalent resistance of a parallel circuit.

Hall Sensor

Hall Sensor (version 2)

A hall sensor is a simple device designed to measure the change in voltage when the sensor is near magnetic fields using the hall effect, it can then output this as electronic data and received by microcontroller and convert to corresponding magnetic field strength.

Mini Variable Power Supply

Mini Variable Power Supply

The variable power supply is a power supply device with a lightweight design, making it easy to carry. Users can easily adjust the output voltage to meet the needs primarily for electrical experiments.

Old Version
(Requires use with the old Lab in Your Pocket app)

Voltage Sensor


Voltage Sensor (version 1)

The working principles of voltage sensor are a bit complicated and varied from type to type. In general, there exists a voltage divider that allows high voltage measurement. The internal resistance is set high enough to not affect the equivalent resistance of a parallel circuit.


Hall Sensor


Hall Sensor (version 1)

A hall sensor is a simple device designed to measure the change in voltage when the sensor is near magnetic fields using the hall effect, it can then output this as electronic data and received by microcontroller and convert to corresponding magnetic field strength.

PM Sensor


PM Sensor

When a fixed intensity of light beam passes through air, the more particulate matter (PM) scatters the larger proportion of the light beam away to other directions, and hence less light beam hit the photoelectric element on the other side. Photocurrent is triggered when light hit the photoelectric element, which is then converted into density of particulate matter in air by the microcontroller. The values (most commonly seen and health-related are PM2.5 and PM10) represent the diameters of particulates in terms of micrometer (µm).

Oxygen and Carbon Dioxide Sensor


Oxygen and Carbon Dioxide Sensor

The oxygen sensor involves electrochemical mechanism which makes use of the linearity between an output voltage against concentration of oxygen. Carbon dioxide, on the other hand, is measured by similar method as PM sensor but this time Infrared is adapted instead and you know - carbon dioxide is a greenhouse gas perfectly absorb Infrared radiation.

UV and Soil pH Sensor


UV and Soil pH Sensor

Similar to light sensor, UV sensor consists of a photocell that generates photocurrent upon a specific range of Ultraviolet radiation. Soil pH sensor contains anode and cathode that utilizes the very defining nature of pH - concentration of Hydrogen atoms. The higher conductivity, so as current, infers higher concentration of Hydrogen atoms (more acidic, lower pH).

Temperature and Light Sensor


Temperature and Light Sensor

These sensors work in above-mentioned principles. The electrical output across a thermoresistor is used to determine temperature. The light sensor relies on the famous photoelectric effect from Albert Einstein where photocurrent is generated across photocell upon receiving light. The photocurrent is then converted into corresponding light intensity.

Accelerometer


Accelerometer

The design of modern digital accelerometer is electronically a bit complicated yet physically simple. Instead of a metal ball, the accelerometer contains structure known as "polysilicon springs" in 3 axes that deform upon inertial movement and give different capacitance. Our team decided to develop an external accelerometer even though we easily have one in mobile devices - to allow more vigorous testing without risking your valuable smartphones!


LabXRA

Department of Applied Physics
The Hong Kong Polytechnic University


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