Vernier IRT-BTA User manual

Infrared Thermometer
(Order Code IRT-BTA)
The Infrared Thermometer is a non-contact, fast-
responding temperature measuring device. The sensor
works by measuring the infrared radiation emitted by
objects. For most objects, you simply point the sensor at the object and read its
temperatures. Here are a few example uses of the sensor.
•Since the sensor responds so quickly, you can easily investigate skin
temperature. For example, compare the temperature of your palm to the back of
your hand, your forearm, or your foot.
•Demonstrate that most objects in the room are at equilibrium. For example, what
is the temperature of the table top that feels cold? Compare its temperature to
the temperature of the wall, the floor, or a book.
•Compare the surface temperatures of cars parked in the sun. Does color affect
the surface temperature? Is the surface hot enough to cook an egg?
•On a sunny day compare the temperature of asphalt, concrete and lawn.
NOTE: This product is to be used for educational purposes only. It is not appropriate for
industrial, medical, research, or commercial applications.
Items Included with the Infrared Thermometer
Check to be sure that each of these items is included in your sensor package:
•Infrared Thermometer (order code IRT-BTA)
•Cable to connect the sensor to a data-collection interface (order code CB-IRT)
•4 AAA batteries
•Infrared Thermometer booklet (this document)
•Omega Infrared Thermometer Manual
SAFETY INFORMATION: This sensor contains a laser that can be turned on and off. As
with any laser, caution must be exercised when using the sensor. The sensor emits laser
radiation, and therefore, should not be pointed at the eye. Pay special attention to the location
of the aperture, which is located next to the sensing element. Direct eye contact with the laser
beam may cause serious injury. Students should be reminded that this is not a toy, and it
should be kept out of reach of children. It is recommended that you read the Omega sensor
booklet that accompanies this sensor. It contains important safety information.
Infrared Thermometer Description
The Infrared Thermometer features automatic backlighting, simple on/off operation,
and laser circle sighting. The sensor can be used as a standalone meter, or it can be
connected to a data-collection interface, e.g., Vernier LabPro®, LabQuest®,
LabQuest®Mini, Go!®Link, CBL 2™, and Vernier EasyLink®, SensorDAQ®,
allowing data to be recorded on a computer, Texas Instruments graphing calculator,
or Palm Powered™handheld.
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The sensing element of the Infrared Thermometer is located at the end of the sensor.
The sensor reading will appear in °C. When connected to a data-collection interface,
data can be collected in other units, e.g., °F and K. To the side of the sensing
element, you will find a clear plastic window. Behind this window is a laser that is
used to aim the sensor. Do not look into this window when the laser is enabled.
The infrared temperature measurement of this sensor is based on a fixed value for
the emissivity of the object. This value works well for lots of everyday objects, e.g.,
skin, wood, concrete, water, and glass; however there are objects that do not lend
themselves to this measurement, such as shiny metals. (See the section entitled
“How the Infrared Thermometer Works” for further information).
The sensor has a built-in light sensor located next to the MEAS button. This sensor
controls the automatic backlighting feature.
The Infrared Thermometer is powered by 4 AAA batteries that are inserted into the
back of the sensor. When the batteries are low, a low battery indicator will appear on
the LCD.
Panel Buttons
MEAS–This button turns the meter power on and off. When you press it once, the
meter turns on. It will remain powered for 30 minutes, at which time it will
automatically turn off. If you want to turn it off before then, press the MEAS button
a second time.
Hold–The Hold button is primarily used in the stand-alone mode. You can press the
button to hold the current meter on the screen. The sensor output also remains at that
value. If you are connecting the sensor to a data-collection interface, you probably
will not use this button.
Laser button ()–The laser button turns on a laser that shows a circular pattern. The
pattern helps you identify the region from which the measurement is made. Note that if you
are holding the object very close to the thermometer, parallax may prevent the laser sighting
circle from representing the measurement area.
Operating the Infrared Thermometer
Here are the general operating procedures:
1. Turn the sensor over, remove the small screw on the back, and insert 4 AAA
batteries. Replace the battery cover.
2. Press the MEAS button and point the sensor at an object to determine its
temperature.
3. The temperature measurement is made from a circular region. This circular
region gets larger as the sensor is moved away from the object. To better
determine the region of the measurement, press the laser button ( ). The
circular pattern shows the main region from which the measurement is made. To
improve the accuracy, the measurement region should be 1.5 to 2 times the size
of the circular laser pattern.
4. To turn the sensor off, press the MEAS button. Note: The sensor will
automatically shut off in 30 minutes.

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Connecting the Infrared Thermometer to Vernier products
The Infrared Thermometer package includes a removable cable (order code
CB-IRT). Connect the mini-plug end of the cable into the bottom of the sensor.
Connect the other end to the data-collection interface, e.g., Vernier LabPro,
LabQuest, Go! Link, CBL 2, EasyLink, or SensorDAQ.
Collecting Data with the Infrared Thermometer
This sensor can be used with the following interfaces to collect data:
•Vernier LabQuest as a standalone device or with a computer
•Vernier LabQuest Mini with a computer
•Vernier LabPro with a computer, TI graphing calculator, or Palm®handheld
•Vernier Go!Link
•Vernier EasyLink
•Vernier SensorDAQ
•CBL 2
Here is the general procedure to follow when using the Infrared Thermometer:
1. Connect the Infrared Thermometer to the interface.
2. Start the data-collection software1.
3. The software will identify the Infrared Thermometer and load a default data-
collection setup. You are now ready to collect data.
Data-Collection Software
This sensor can be used with an interface and the following data-collection software.
•Logger Pro 3 This computer program is used with LabQuest, LabQuest Mini,
LabPro, or Go!Link.
•Logger Pro 2 This computer program is used with ULI or Serial Box Interface.
•Logger Lite This computer program is used with LabQuest, LabQuest Mini,
LabPro, or Go!Link.
•LabQuest App This program is used when LabQuest is used as a standalone
device.
•EasyData App This calculator application for the TI-83 Plus and TI-84 Plus can
be used with CBL 2, LabPro, and Vernier EasyLink. We recommend version
2.0 or newer, which can be downloaded from the Vernier web site,
www.vernier.com/easy/easydata.html, and then transferred to the calculator.
See the Vernier web site, www.vernier.com/calc/software/index.html for more
information on the App and Program Transfer Guidebook.
•DataMate program Use DataMate with LabPro or CBL 2 and TI-73, TI-83,
TI-84, TI-86, TI-89, and Voyage 200 calculators. See the LabPro and CBL 2
Guidebooks for instructions on transferring DataMate to the calculator.
•Data Pro This program is used with LabPro and a Palm handheld.
1If you are using Logger Pro 2 with either a ULI or SBI, the sensor will not auto-ID.
Open an experiment file for the Low-g Accelerometer in the Probes & Sensors
folder.
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•LabVIEW National Instruments LabVIEW™ software is a graphical
programming language sold by National Instruments. It is used with
SensorDAQ and can be used with a number of other Vernier interfaces. See
www.vernier.com/labview for more information.
Specifications
Temperature range: –20°C to 400°C
Operating temperature range: 0°C to 50°C at < 70% relative humidity
Display Resolution: 1 °C
Accuracy: ±2% of reading or ±3°C, whichever is greater @ 18 to 28°C ambient
operating temperature
Response time: 1 second
Display Resolution on the meter: 1 °C
Spectral Response: 6 to 14 μm nominal
Emissivity: preset 0.95
Detection element: Thermopile
Field of view: 65 mm diameter circle at 1000 mm range
Average battery life: 100 hours typical (laser and backlight not illuminated)
This sensor ships with a cable that is equipped with circuitry that supports auto-ID. When
used with LabPro, LabQuest, LabQuest Mini, Go!Link, CBL 2, or EasyLink, the data-
collection software identifies the sensor and uses pre-defined parameters to configure an
experiment appropriate to the recognized sensor. This greatly simplifies the setup procedures
for many experiments.
How the Infrared Thermometer Works
All objects emit infrared radiation, and the amount emitted is proportional to the
object’s temperature and its ability to emit infrared radiation. This ability called
emissivity is based on the material of the object and its surface finish. Emissivity
values range from 0.10 to 1.00 for a perfect black body. (See the chart below.) This
sensor makes its measurement based on a fixed emissivity of 0.95 which covers most
everyday objects. This sensor and all other infrared thermometers do not accurately
measure the temperature of shiny substances, e.g., polished metals, etc. To measure
the temperature of shiny objects, paint them with a flat paint or cover them with tape.
Also, if the object is covered by frost or another material, clean it to expose the
surface. If the sensor appears to measure incorrectly, check the front cone of the
sensor. It may be covered with condensation or debris. If necessary, wipe it with a
clean cloth.
To measure temperature, this sensor gathers infrared radiation in the 6 to 14 μm
wavelength range. A Fresnel lens on the front of the sensor focuses the radiation
onto the sensing element. The observed spectral distribution is used to determine the
object’s temperature assuming standard blackbody radiation with an emissivity of
0.95.

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Another consideration in this measurement is the field of view. The field of view is
the angle of vision at which the measurement is made. One of the valuable features
of this sensor is the laser sighting pattern which helps you identify the field of view.
The field of view and the spot almost coincide. The object that you are measuring
should fill the field of view, or better yet be 1.5 to 2 times size of the circular spot.
The laser sighting circle is great help in identifying the measurement region;
however be aware that if you are measuring small objects, e.g., approaching the size
of the sensor window, you will need to hold them close to the sensor. In that
arrangement parallax may prevent the laser circle from matching the measurement
reading.
Table of Emissivities
Substance Thermal emissivity Substance Thermal emissivity
Asphalt 0.90 to 0.98 Plaster 0.80 to 0.90
Concrete 0.94 Mortar 0.89 to 0.91
Cement 0.96 Red brick 0.93 to 0.96
Sand 0.90 Black cloth 0.98
Earth 0.92 to 0.96 Human skin 0.98
Water 0.92 to 0.96 Lather 0.75 to 0.80
Ice 0.96 to 0.98 Charcoal powder 0.96
Snow 0.83 Rubber (black) 0.94
Glass 0.90 to 0.95 Plastic 0.85 to 0.95
Ceramic 0.90 to 0.94 Timber 0.90
Marble 0.94 Paper 0.70 to 0.94
Calibration
This sensor is factory calibrated and not designed to be recalibrated.
Stored Calibrations for the Infrared Thermometer
For °C Slope = –84.388 °C/V Intercept = 398.19 °C
For °F Slope = –151.9 °F/V Intercept = 748.74 °F
For Kelvin Slope = –84.388 K/V Intercept = 671.34 K
Use in the Classroom
This sensor lets you collect measurements that would be difficult if not impossible to
make. Here are some classroom uses for the sensor.
Understanding Temperature
Temperature can be difficult concept to understand. Our personal experiences
complicate the situation. Imagine being a grade school student in a classroom on a
hot day in September. Your arm touches the metal leg of the desk, and you discover
that the metal is cold. When you touch the top of your desk, it’s not cold. As a matter
of a fact most of the objects in the room are not cold. The infrared thermometer
would be a perfect sensor for this teachable moment. A student could use it to
discover that the temperature of the metal leg of the desk is the same as the desk top,
which is the same as the temperature of the wall, door, textbook, etc. This
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knowledge helps students better understand temperature, equilibrium and thermal
conductivity. This experiment could lead to a field trip to the school’s parking lot.
With the sun shining brightly on the cars, the students could compare the
temperatures of the surfaces of cars. Are these temperatures the same, or does the
color of the car make a difference? Is the surface of the car hot enough to fry an egg?
They could expand their exploration to compare temperatures of the lawn, concrete
and asphalt.
The Drinking Bird Demo
More than likely you are familiar with the “Drinking Bird” toy. The bird sits on a
stand that allows it to rotate about a pivot point. After the “head” of the bird, which
is covered with felt, is wetted, the bird oscillates about the pivot point while a liquid
moves up and down a tube connecting the head and bottom of the bird. A number of
concepts can be discussed when explaining the motion of the bird. They include
center of gravity, vapor pressure, temperature, equilibrium, etc. An important part of
the explanation centers around understanding what happens to the temperature of the
bird’s head. Since the head is covered with moist felt, we can hypothesize that
evaporation is occurring at the bird’s head. Since evaporation is a cooling process,
the head must be cooling, and the drop of vapor pressure in the bird’s head
contributes to the rise of the liquid in the tube. Without this sensor, you don’t have
direct evidence that the bird’s head is cooling. With this sensor you can verify the
hypothesis. We tried it and found that the temperature of the felt before adding water
was 25 °C. We measured the temperature again after wetting the head and letting the
bird oscillate for 10 minutes. The temperature had dropped to 19 °C.
Investigating Skin Temperature
Since the sensor responds very quickly, you can easily investigate skin temperature.
For example, simply point the sensor at your palm to determine its temperature.
Compare that reading to the back of your hand, your forearm or your foot. After
measuring the temperature of your forearm, cover it with a shirt and take another
reading. Is the temperature the same? Open your mouth and take the temperature.
How does its temperature compare to skin temperature? Next take the temperature of
hair on the top of you head. How does it compare to the previous temperatures?
Evaporation and Intermolecular Attraction lab
A popular experiment from our chemistry lab manual is the Evaporation and
Intermolecular Attraction lab. In this experiment students wrap filter paper around
two temperature probes. They then wet the filter paper with room temperature
hydrocarbons, e.g., methanol, ethanol, pentane, etc. Next they expose the probe to air
and collect temperature data as the hydrocarbons evaporate. They repeat the
experiment two more times with other pairs of hydrocarbons. Each data-collection
run takes four minutes in addition to the preparation time. In the end the students
relate the temperature change to the strength of intermolecular forces of attraction.
The Infrared Thermometer could be used to simplify this experiment. The students
would start by measuring the temperature of dry room-temperature filter paper. They
then place separate pieces of paper in different hydrocarbons. The filter papers could
be laid out on a rack for evaporation to occur. The sensor could then be used to

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quickly record the final temperature of each paper. The disadvantage to this
approach is that students do not have a record of change of temperature as a function
of time.
Warranty
This product is manufactured by OMEGA Engineering. OMEGA warrants it to be
free from defects in materials and workmanship for a period of 13 months from the
date of shipment to the customer. This warranty does not cover damage to the
product caused by abuse or improper use.
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Vernier Software & Technology
13979 S.W. Millikan Way •Beaverton, OR 97005-2886
Toll Free [phone] •[phone] •FAX [phone]
[email protected] •www.vernier.com
Rev.2/17/10
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