DESIGN OF DATA LOGGER USING LabVIEW A PROJECT REPORT Submitted by SAAJAN DEHURY [Reg No: 11707067] SAURABH GUPTA [Reg No: 11707073] SIDDHARTH PANICKER [Reg No: 11707077] Under the guidance of Mrs. B.HEMALATHA (Assistant Professor, Department of Instrumentation and Control Engineering) in partial fulfilment for the award of the degree of BACHELOR OF TECHNOLOGY in ELECTRONICS AND INSTRUMENTATION ENGINEERING of FACULTY OF ENGINEERING & TECHNOLOGY 1
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etc, we need regular information regarding meteorological parameters and their
values.
After recording this information, we are transferring this data using
communication protocols like SMTP. All this is being done using LabVIEW,
which is faster and more efficient software.
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ACKNOWLEDGEMENT
Apart from the efforts of me, the success of this project depends largely on the
encouragement and guidelines of many others. I take this opportunity to express my gratitude
to the people who have been instrumental in the successful completion of this project.
I would like to show my greatest appreciation to Assistant Professor Mrs.B.Hemalatha. I
can’t say thank you enough for her tremendous support and help. I feel motivated and
encouraged every time I attend her meeting. Without her encouragement and guidance this
project would not have materialized.
The guidance and support received from all the team members including Saurabh Gupta
and Siddharth Panicker who contributed and are contributing to this project, was vital for the
success of the project. I am grateful for their constant support and help.
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TABLE OF CONTENTS
CHAPTER NO. PAGE NO.
ABSTRACT 2
LIST OF TABLE 6
LIST OF FIGURES 7
1. INTRODUCTION 8
2. SURVEY 12
3. SENSORS AND COMPONENTS 18
3.1 HUMI DITY SENSORS 19
3.2 TEMPERATURE SENSORS 22
3.3 PRESSURE SENSORS 26
3.4 AMPLIFIER CIRCUIT 31
3.5 VOLTAGE REGULATOR/IC7805 33
3.6 VOLTAGE REGULATOR/IC7812 39
3.7 VOLTAGE REGULATOR/IC 7815 40
4. BLOCK DIAGRAMS 41
5. LabVIEW 43
6. COMMUNICATION 57
7. FUTURE ENHANCEMENTS 59
8. CONCLUSION 60
9. REFERENCES
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LIST OF TABLES
Table Page
1. Temperature Survey 12
2. Specifications of humidity sensor 19
3. Standard characteristics of humidity sensor 20
4. Absolute Maximum ratings of Pressure Sensor 29
5. Maximum ratings of amplification IC 7805 36
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LIST OF FIGURES Page
Chapter 1
1. Hourly average of temperature 13
2. Daily variation of temperature 14
3. Daily variation of temperature 15
4. Daily variation of temperature 16
Chapter 21. Humidity sensor SY-HS-220 18
2. Characteristic curve of Humidity Sensor 21
3. Pin configuration of Temperature Sensor 23
4. Connection of Temperature Sensor 24
5. Connection of Pressure Sensor 27
6. Internal circuit diagram of LM324 31
7. Pin layout of IC7805 33
8. Internal Block diagram of IC7805 35
9. Top view of TO-220 packaging 38
Chapter 31. Amplification circuit 40
2. Connection of LM35DZ with the amplification IC LM324 41
3. Connection of pressure sensor ICS 1220 with amplification IC LM324 42
Chapter 41. NI USB-6008 45
2. Creation of sender’s e-mail id 46
3. Activation of SMTP 47
4. Storing data in the file 48
5. Acquiring the signals & filtering 49
6. Front panel depicting controls & indicators 50
7. Selecting the measurement type 51
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8. Selecting the measurement type 52
CHAPTER 1
INTRODUCTION
Data loggers vary between general purpose types for a range of measurement
applications to very specific devices for measuring in one environment or application type
only. It is common for general purpose types to be programmable; however, many remain as
static machines with only a limited number or no changeable parameters. Electronic data
loggers have replaced chart recorders in many applications.
One of the primary benefits of using data loggers is the ability to automatically collect
data on a 24-hour basis. Upon activation, data loggers are typically deployed and left
unattended to measure and record information for the duration of the monitoring period. This
allows for a comprehensive, accurate picture of the environmental conditions being
monitored, such as air temperature and relative humidity.
With the development of computer technology, modern measurement technology, and
electronic instrument technology, virtual instrument becomes mainstream direction of current
instrument development because of its characteristics of high efficiency, man-machine
interactive interface good, convenience of reconstructed system, self-defining function, and
so on.
Designing this system used this method can improve the detection of wind speed,
temperature, humidity. At the same time, a user can operate this system only by using
keyboard or mouse. In a word, this system constructed by this way becomes convenient.
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LabVIEW contains a comprehensive set of tools for acquiring, analyzing, displaying, and
storing data, as well as tools to help us troubleshoot code we write.
In LabVIEW, we can build a user interface, or front panel, with controls and indicators.
Controls are knobs, push buttons, dials, and other input mechanisms. Indicators are graphs,
LEDs, and other output displays. After we build the user interface, we add code using VIs
and structures to control the front panel objects. The block diagram contains this code. We
can also use LabVIEW to communicate data to other devices.
Also, data acquisition is easy in LabVIEW. Sensors are used for measuring temperature
and humidity. By constructing an amplification circuit, the properly calibrated values can be
obtained.
By using temperature sensor LM35DZ and humidity sensor HS-SY220, we can get the
temperature and relative humidity in the ambient atmosphere.
By using pressure sensor ICS1220, we can get the pressure in the ambient atmosphere.
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Advantage of Data Logger over other collection instruments
Three types of instruments are commonly used for collecting and storing data. They are:
Real-Time Data Acquisition Systems
Chart Recorders
Data Loggers
Data loggers are normally more economical than chart recorders. They offer more
flexibility and are available with a greater variety of input types. Most data loggers collect
data which may be directly transferred to a computer. Although this option is available
with some recorders, it normally adds significant expense to the recorder price.
Data acquisition systems offer a great deal of flexibility and are certainly attractive when
high sample rates are required, however, since they require connection or installation into a
computer, the computer must also be present and active when collecting the data. Data
loggers can collect data independently of a computer. Data is normally collected in non-
volatile memory for later download to a computer. The computer does not need to be present
during the data collection process. This makes them ideally suited for applications requiring
portability.
The Maximum Sample Rate for a Data Logger
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The sample rate depends on the specific model. Although most data loggers have a
maximum data rate of 1 or 2 samples per second, some data loggers can sample in excess of
100 samples per second.
Power Source for Data Loggers
Most data loggers are battery powered some also offer an option for external power.
Parameters involved in the battery life of a Data Logger
The battery life of a data logger depends on a number of parameters including the specific
model and sample rate. In general the faster the sample rate the shorter the battery life.
Recording Duration
The recording duration is dependent on the memory capacity of the data logger and the
desired sample rate. To determine the duration divide the memory capacity (number of
samples the device can record) by the sample rate. As an example assume that a given data
logger can store 10,000 samples. If it is desired to record 2 samples every minute, the data
logger can run for 10,000/2 or 5,000 minutes (about 3.5 days). If the sample rate was cut in
half (1 sample per minute), the recording period would double to 7 days.
CHAPTER 2
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SURVEY
Presented in the following few pages is the results of a survey that has been done. This
survey includes values and trends of various metrological parameters.
Table 1: Temperature survey
The above given data is obtained from the campus of SRM University, and was taken in
the year 2009-2010. The temperature sets given are the monthly maximum and minimum
temperature values obtained. Based on this empirical data, many experiments of high
importance can be carried out with a high efficacy.
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Fig. 1: Hourly average for Temperature
The data is then taken and plotted on a graph. A trend is obtained, which is depicted above.
The following results can be obtained from the aforementioned data:
• Temperatures vary between 24 and 35 deg with lower averages in the beginning of
2010.
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Fig. 2: Daily variation of temerature
Daily variation of temperature from July-2009 to August-2009
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Fig.3: Daily variation of temperature
Daily variation of temperature from September-2009 to December-2009
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Fig.4: Daily variation of temperature
Daily variation of temperature from January 2010 to February 2010
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CHAPTER 3
SENSORS AND COMPONENTS
In this chapter, all the sensors and other components used in the project are discussed.
The sensors and components form the most important part of our project, the electronics.
A humidity sensor is an instrument used for measuring the moisture content in the
environmental air, or humidity. Humidity is difficult to measure accurately. Most
measurement devices usually rely on measurements of some other quantity such as
temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is
absorbed. From calculations based on physical principles, or especially by calibration with a
reference standard, these measured quantities can lead to a measurement of humidity. The
humidity sensor is a four-terminal device.
A temperature sensor is a device that measures temperature or temperature gradient using
a variety of different principles. The temperature sensor accurately measures the temperature,
and gives an electrical voltage as output when the temperature is given as an input. The
temperature sensor device is a three-terminal device.
A pressure sensor is a device that takes the atmospheric pressure as an input, and gives a
corresponding electrical signal as an output. The pressure sensor used here is an eight-
terminal device.
The output signals of all the sensors have to be amplified. For that purpose, we design an
amplifier circuit.
The power source should give a regulated voltage as source. For that purpose, a voltage
regulator is being used.
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1. HUMIDITY SENSOR SY-HS-220
Fig. 1: Humidity sensor SY-HS-220
The humidity sensor SY-HS-220 is a four-terminal device, and it takes the humidity from the atmosphere as the input, and gives electrical signal as the output.
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Table 2:Specifications of Humidity Sensor
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Table 3:Standard characteristics of Humidity Sensor
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Fig. 2: Characteristics Curve for Humidity Sensor
2. TEMPERATURE SENSOR LM35DZ
The LM35 series are precision integrated-circuit temperature sensors, whose output
voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has
an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required
to subtract a large constant voltage from its output to obtain convenient Centigrade scaling.
The LM35 does not require any external calibration or trimming to provide typical
accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature
range. Low cost is assured by trimming and calibration at the wafer level.
The LM35’s low output impedance, linear output, and precise inherent calibration make
interfacing to readout or control circuitry especially easy. It can be used with single power
supplies, or with plus and minus supplies. As it draws only 60 μA from its supply, it has very
low self-heating, less than 0.1°C in still air.
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The LM35 is rated to operate over a −55° to +150°C temperature range, while the
LM35C is rated for a −40° to +110°C range (−10° with improved accuracy). The LM35
series is available packaged in hermetic TO-46 transistor packages, while the LM35C,
LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The
LM35D is also available in an 8-lead surface mount small outline package and a plastic TO-
220 package.
FEATURES
1. Calibrated directly in ° Celsius (Centigrade)
2. Linear + 10.0 mV/°C scale factor
3. 0.5°C accuracy guaranteeable (at +25°C)
4. Rated for full −55° to +150°C range
5. Suitable for remote applications
6. Low cost due to wafer-level trimming
7. Operates from 4 to 30 volts
8. Less than 60 μA current drain
9. Low self-heating, 0.08°C in still air
10. Nonlinearity only ±1⁄4°C typical
11. Low impedance output, 0.1 W for 1 mA load
The above given features are of the temperature sensor, LM35DZ. The linearity of the
LM35DZ, and its high accuracy make it a very viable choice for our project.
It is a low cost high efficiency model. It also has a very wide range of -55° to +150°C,
which comprises all our possible outputs.
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CONNECTION DIAGRAMS
Fig. 3:Pin configuration of Temperature Sensor
The above shown sensor is a three-terminal device. The first terminal is the supply
voltage terminal, where the supply is provided. The third terminal is the ground terminal,
which is always grounded. The second terminal is the output voltage terminal. To see the
output, this terminal has to be checked. The output voltage is taken out from the second
terminal. To check the output voltage, a voltmeter should be connected in between the second
and the third terminal.
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APPLICATION
Fig. 4:Connection of Temperature Sensor LM35DZ
The above shown diagram is of LM35DZ, the temperature sensor. It is a three-terminal
device, with the second terminal, i.e. the output terminal, connected to a resistance R1. The
value of R1 is computed based on the above given formula.
Absolute Maximum Ratings
1. Supply Voltage +35V to −0.2V
2. Output Voltage +6V to −1.0V
3. Output Current 10 mA
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3. Pressure Sensor / ICS1220
The ICS1220 series of solid state pressure sensors are designed to provide a cost effective
solution for applications that require calibrated performance over a wide temperature range.
Packaged in a dual-in-line configuration, the ICS1220 series is intended for printed circuit
board mounting. Optional pressure port and lead configurations give superior flexibility in
low profile applications where pressure connection orientation is critical. The ICS1220 series
is based on NovaSensor’s advanced SenStable piezoresistive sensing technology.
Silicon micromachining techniques are used to ion implant piezoresistive strain gages
into a Wheatstone bridge configuration. The ICS1220 offers the added advantage of superior
temperature performance over the temperature compensated range of 0°C to +60°C. A
current set resistor is included to normalize the full scale output for field interchangeability.
Additionally, the ICS1220 series is available in pressure ranges from 0 to 5 through 0 to 100
psi.
Integral temperature compensation is provided over a range of 0-50°C using laser-
trimmed resistors. An additional laser-trimmed resistor is included to normalize pressure
sensitivity variations by setting the current drive to the sensor bridge, resulting in an
interchangeability of ±1% prior to amplification.
Gage, absolute, and differential pressure ranges from 0-2 PSI to 0-100 PSI are available.
Multiple lead and tube configurations are also available for customizing the package for
specific applications.
A few important features of pressure sensor ICS1220 are given below. These features are very conducive to our project, and these features are the reasons why we have selected ICS1220 for our project.
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Features
• 50 mV Full-scale Output
• ±0.1% accuracy
• Interchangeable
• Temperature Compensated 0°C to 60°C
• PCB mountable package
• DIP package
• Solid state reliability
• Individual device traceability
The high accuracy of ICS1220, and the interchangeability makes it a very good option for
our project.
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Pressure Ranges
• Gauge and differential
5, 15, 30, 50 and 100psi
• Absolute: 15, 30, 50 and 100psi
(5psi: call Nova Sensor)
Fig.5:Connection diagram of Pressure Sensor
The above given circuit is the pressure sensor circuit. The dotted boundary is the pressure
sensor, and as shown it has eight terminals. A1 is an operational amplifier, and the output is
taken from the first and the third terminals of the pressure sensor.
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1. For 2 psi output on a 5 psi sensor span is 20.0 mV ± 1%, amplified span is 1.232V and
zero temperature error is ±1.25%.
2. Compensation resistors are an integral part of the sensor package; no additional external
resistors are required. Pins 7 and 8 must be kept open.
3. Best Fit Straight Line.
4. Temperature range: 0-50°C in reference to 25°C.
5. For a zero-to-full scale pressure step change.
6. 10 Hz to 1 kHz.
7. Prevents increase of TC-Span due to output loading.
8. 3X or 200 psi maximum, whichever is less. 20 psi for 2 psi and 5 psi versions.
9. Wetted materials are glass, ceramic, silicon, RTV, nickel, gold, and aluminum.
10. Soldering of lead pins: 250°C for 5 seconds maximum.