DESIGN AND DEVELOPMENT OF A PORTABLE NEAR-INFRARED SPECTROSCOPY (NIRS)By: Nur Hasinah Binti Hanis (AE110106)SV: Dr Chia Kim SengPanels: Dr Rosli Bin Omar

Ir. Dr Babul Salam Bin KSM Kader Ibrahim

CHAPTER 1INTRODUCTION

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.

PROBLEM STATEMENTS

Not portable • difficult to use on field

Time consuming

• must be brought FIRST to the laboratory for testing

OBJECTIVES

To develop a portable NIR SpectroscopyTo measure the wavelength of the different fruits

SCOPE OF PROJECTThe wavelength of LEDs were selected; 740nm, 850nm and

940nmUsing LED as the light source

Photodiode OPT101 was selected as a sensor

Rechargeable battery was used as a power supplyWavelength intensity will be

displayed using LCDThe pineapple, pear and mango will

be used as a sample

CHAPTER 2LITERATURE REVIEW

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 .

There are three physical principles of NIRS;

• happen to specific wavelength• determined by the molecular properties of the

material within the light pathLight

Absorption

• travels direction relies upon the wavelengthLight Scattering 𝐴=log 𝐼𝐼𝑂 =𝜀0 𝐶.𝑑Light Attenuation

EXISTING RELATED WORKS

Spectrophotometer built in Nicaragua DIY Spectro II

A Low cost LED based Spectrophotometer

Camera Phone used as a spectrophotometer

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.

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.

Case Study II: SpectuinoThe 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.

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.

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.

☻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.

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.

CHAPTER 3RESEARCH METHODOLOGY

PROJECT OVERVIEW

Block Diagram of a NIR Spectrometer

Light Source Sample Spectrometer Microcontroller

LCD Display

▪ Flow Chart for NIR Spectrometer

START

CALIBRATION

MEASURE SAMPLE

WAVELENGTH?

RESET

DISPLAY

CHAPTER 4PRELIMINARY RESULT

SCHEMATIC DESIGN

Multi LED connection with OPT101

PCB DESIGN

CHAPTER 5EXPECTED RESULT

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.

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

.2w9/10/20149/10/2014Submission 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

.2w4/12/20144/12/2014Submission Seminar Paper to Panels

15

16

17

18

.2w8/12/20148/12/2014Mock Presentation 1

.2w11/12/201411/12/2014PSM 1 Presentation

.2w31/12/201431/12/2014Submission Report PSM1 & Log Book to SV1

16.6w31/12/20148/9/2014TOTAL DAYS

☻Q & A

END

☺☺☺ THANK YOU ☺☺☺