The document outlines the design and development of a portable near-infrared spectroscopy (NIRS) device. It discusses using specific infrared LED wavelengths between 750-950nm along with the OPT101 photodiode to detect intensity levels of the wavelengths. An Arduino microcontroller will be used to connect the infrared circuit to an LCD display to show measurement results. The goal is to create a portable NIRS sensor that is small, low-cost, and able to measure the wavelengths of different fruits to analyze their chemical properties.

1. DESIGN AND DEVELOPMENT OF
A PORTABLE NEAR-INFRARED
SPECTROSCOPY (NIRS)
By: Nur Hasinah Binti Hanis (AE110106)
SV: Dr Chia Kim Seng
Panels: Dr Rosli Bin Omar
Ir. Dr Babul Salam Bin KSM Kader Ibrahim

2. CHAPTER 1
INTRODUCTION

3. BACKGROUND OF STUDY
Near-infrared spectroscopy (NIRS) a sensor that can be used non-
destructively to measure the quality of food.
The examples of the application
predicting soluble solids content of pineapple
predicting soluble solids content of pear
sugar measuring in mango.
With LEDs and sensor that will be developed, it is POSSIBLE to
construct small, portable and low cost NIRS instruments that can
analysis the chemical compounds relevant for diagnosis and
monitoring.

4. PROBLEM STATEMENTS
Not portable
• difficult to use on field
Time
consuming
• must be brought FIRST to the
laboratory for testing

5. OBJECTIVES
To develop a portable NIR Spectroscopy
To measure the wavelength of the different fruits

6. SCOPE OF PROJECT
The wavelength of LEDs were selected;
740nm, 850nm and 940nm
Using LED as the light source
Photodiode OPT101 was selected as a sensor
Rechargeable battery was used as a power
supply
Wavelength intensity will be displayed using
LCD
The pineapple, pear and mango will be used
as a sample

7. CHAPTER 2
LITERATURE REVIEW

8. INTRODUCTION
NIR is a spectroscopic technique based on molecular overtones
and combination vibration of a particular atom.
Vibration spectroscopic technique belongs to the IR light spectrum
from regarding 750 to 2500 nm known as Near-Infrared spectrum.
In IR region, the molar absorption factor is incredibly small.
The wavelength about 718nm, 768nm and 856nm have a
prestigious wavelengths as the predictors of prophetical models
achieved higher prophetical accuracy, compared to that used
either the complete spectrum or the chosen spectral segments in
solid sample .

9. There are three physical principles of NIRS;
• happen to specific wavelength
• determined by the molecular properties of the material within the light path
Light Absorption
• travels direction relies upon the wavelengthLight Scattering
• 𝐴 = log
𝐼
𝐼 𝑂
= 𝜀0 𝐶. 𝑑Light Attenuation

10. EXISTING RELATED WORKS
Spectrophotometer
built in Nicaragua
DIY Spectro II
A Low cost LED based
Spectrophotometer
Camera Phone used as
a spectrophotometer

11. DESIGN AND CONCEPT SELECTION
Case Study I: SLIM Spectrometer
 know as a Simple, Low-power, Inexpensive and Microcontroller-based.
 SLIM design that has utilized are noisier and has lower resolution than standard
models.


12. TSL230 programmable light-to-frequency converter is a photodetector.
This IC a configurable grid of photodiodes and a current-to-frequency
converter in a single package.
This photodetector is ideals of this application because no separate ADC chip
or domain converters are required. TSL230 is the best photodetector for
ultraviolet-to-visible-light in range of 300 nm to 700 nm.

13. Case Study II: Spectuino
The monochromator and costly light source is replaced with a microcontroller
and LED.
The programming of the Arduino may make this device as accurate as any
spectrophotometer in the market.

14. Two simple buttons to choose from the “learning” and “identify” mode make
it user-friendly.
The learn mode a better-known sample is tested and its values are kept
within the database of the Arduino.
In the identify mode, the five led are shone at the sample and an algorithmic
program identifies the liquid.

15. Case Study III: Monolithic Photodiode
☻A photo-detector is used to convert the light signal into electrical signals.
☻to detect the signal, an amplifier is added directly after the photo-detector.

16. ☻OPT101 is a combination of a photodiode and transimpedence amplifier in
the same chip
☻REDUCE some drawbacks like leakage currents, Interferences, and parasitic
capacitances
☻OPT101 gives VERY GOOD spectral responsitivity for IR from 800nm to
950nm.

17. SUMMARY
☼the best choice to design NIR spectroscopy is using specific wavelength of
IR LED in between 750nm to 950nm because the photodiode OPT101 give a
good result of detecting for that range of spectrum.
☼An Arduino will be used to connect the IR circuit with the LCD.

18. CHAPTER 3
RESEARCH METHODOLOGY

19. PROJECT OVERVIEW
Block Diagram of a NIR Spectrometer
Light
Source Sample Spectrometer Microcontroller
LCD
Display

20. ▪ Flow Chart for NIR Spectrometer
START
CALIBRATION
MEASURE
SAMPLE
WAVELENGTH?
RESET
DISPLAY

21. CHAPTER 4
PRELIMINARY RESULT

22. SCHEMATIC DESIGN
Multi LED connection with OPT101

23. PCB DESIGN

24. CHAPTER 5
EXPECTED RESULT

25. EXPECTED RESULT
▪ Designing the NIRS sensor in suitable size to be portable device with 50mm
in width and 40mm in height of IR circuit.
▪ The sensor only detect the sending wavelength intensity of selective
wavelength of LED for 740nm, 850nm and 940nm.

26. PROJECT PLAN (PSM1)
ID Task Name Start Finish Duration
Sep 2014 Oct 2014 Nov 2014 Dec 2014
7/9 14/9 21/9 28/9 5/10 12/10 19/10 26/10 2/11 9/11 16/11 23/11 30/11 7/12 14/12 21/12
1 1.2w15/9/20148/9/2014Title Selection
2 4.2w8/10/201410/9/2014Project Research
3 1w16/9/201410/9/2014Problem Statement & Objectives
4 12.8w8/12/201410/9/2014Materials Selection
5 .8w16/9/201411/9/2014Scope
6
7
8
9
10
11
12
4.2w9/10/201411/9/2014Proposal
.2w2/10/20142/10/2014Submission Proposal to SV
.2w9/10/20149/10/2014
Submission Proposal to Dept.
Coordinator
8w2/12/20148/10/2014Design
8.8w8/12/20148/10/2014Development
4w7/11/201413/10/2014Testing & Review
5.8w4/12/201427/10/2014Seminar Paper
13
14
.2w27/11/201427/11/2014Submission Seminar Paper to SV
.2w4/12/20144/12/2014
Submission Seminar Paper to
Panels
15
16
17
18
.2w8/12/20148/12/2014Mock Presentation 1
.2w11/12/201411/12/2014PSM 1 Presentation
.2w31/12/201431/12/2014
Submission Report PSM1 & Log
Book to SV1
16.6w31/12/20148/9/2014TOTAL DAYS

28. END
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