Do-it-yourself cardboard thermometer. Do-it-yourself electronic thermometer Paper thermometer diagram

Today we will tell you how to make an electronic thermometer from three parts with your own hands.

A very simple and fairly accurate thermometer can be made if you accidentally have an old pointer ammeter with a scale of 100 μA lying around.
This will require only two parts.
The temperature is measured by an LM 35 sensor. This integral silicon includes a temperature-sensitive element - a primary converter and a signal processing circuit, made on the same chip and enclosed in a housing, such as, for example, in KT 502 (TO-92). The LM 35 sensor has constructive variety with the same parameters, but a different pinout and heat sink, which is very convenient for contact temperature measurements.
The output voltage of the LM 35 sensor is proportional to the Celsius scale (10mV/C). At a temperature of 25 degrees, this sensor has an output voltage of 250 mV, and at 100 degrees, the output is 1.0 V.
The designation of the sensor is somewhat unusual. The pinout is shown in the figure.

In the diagram, the sensor is depicted as a rectangle with the type designation of the device and the pin numbering.
thermometer is shown in the figure and is so simple that it does not require explanation.
The assembled thermometer must be calibrated.
Turn on the schema. Press the LM 35 sensor firmly against the tank mercury thermometer, for example, with electrical tape, wrap the junction or simply put everything under the pillow. Since any thermal processes are inertial, you will have to wait half an hour or more for the temperatures of the sensor and the thermometer to equalize, then use the potentiometer to set the microammeter needle to the number corresponding to the temperature of the thermometer. That's all. You can use a thermometer.

In the author's version, a thermometer from 0 to 50 degrees Celsius with a division value of 0.1 degrees was used for calibration, so the thermometer turned out to be quite accurate.
Unfortunately, finding such a thermometer is problematic. For rough calibration, you can simply put the sensor next to a thermometer that measures, say, the temperature in the room, wait two hours and set the desired temperature on the scale of the microammeter.
If an accurate thermometer is still found, then a digital multimeter, such as the Chinese BT-308V, can be used as an indicator instead of a dial gauge, then the temperature readings can be read up to tenths of a degree.
For those who want to get acquainted with integrated sensors in detail, please visit kit-e.ru or rcl-radio.ru (search for LM 35).

Technology

3rd grade

Making a thermometer

What is the name of the device that

we determine the temperature?

Thermometer - a device for measuring temperature.

Look at the scale of the thermometer.

What is in the middle of the scale?

Zero marks the boundary between degrees

heat and cold.

S.Kaputikyan

Mom bought a thermometer And attached it to the wall. - Mommy, who is sick? At the neighbors? Behind the wall? - What are you, my dear Alik, There are no sick people in our house, This is a room thermometer - He remembers heat and cold! - So the room is sick, Maybe she's coughing? The temperature has risen, Is that why he looks so gloomy? I will visit the sick I'll let the sun in the window!

Why such a difference in values?

Remember: what is the temperature in winter? What - in the summer?

Our country is huge. In one place in summer the temperature can be only +20⁰, and in another +40⁰.

In our city in winter there are about 15-20 degrees of frost, and in cities located to the north - up to -50.

Those who produce thermometers do not know which city their product will end up in. Therefore, the scale is made such that the thermometer can be used

throughout the entire country.

If the temperature drops, the liquid

in the thermometer falls, if it becomes warmer - the liquid rises.

Materials for the lesson:

white and red threads;
simple pencil;
colored cardboard;
template - scale;
ruler 30cm;
scissors;
glue;

- needle.

template - scale.

2. Take the cardboard of your loved one

colors, draw a rectangle

10 cm wide and 22 cm long.

Cut out along the contour.

3. Gently

paste the template

in the center of the cardboard

rectangle,

it will increase

its service life.

4. Then we need to make "mercury".

1. Take two threads - red and white - each a little more than 2 thermometers long.

2. Connect the threads as shown in the picture:

3. Pull on the threads.

4. Do it at the top

and the bottom of the column

hole thermometer

(places are marked with circles)

and put the threads in there:

red - down

white - up. Pull the threads and tie them

knot with reverse

sides of the thermometer

cut off excess ends.

A thermometer is a necessary tool with which many measure the temperature of the air in the house, water, and also the body. Available for sale various models devices that differ in appearance, measurement method (mercury, infrared, electronic), as well as in cost.

But if you wish, you can make a thermometer from improvised materials with your own hands. The process will require patience and endurance, you will also need ingenuity.

liquid thermometer

Types of thermometers that you can make yourself

A handmade device will last a longer period.

But before proceeding with the manufacture, it is worth considering the types of thermometers:

Model of infrared non-contact thermometer

You can make your own different kinds thermometers - liquid, with mechanical principle works that have metal spirals or ribbons, electronic or digital.

by the most simple option there will be a cardboard product, it is quite simple to make it.

Electronic and digital devices require experience, knowledge of electronics. For their manufacture can be used various schemes that need to be properly connected. Such devices are often used for freezers.

How to make a thermometer

The device can be made from improvised materials that are available at home.

From a plastic bottle

A homemade thermometer from a plastic bottle makes it easy, most importantly, to prepare for the process. To get started you need materials:

plastic bottle 20-25 centimeters high;
tap water;
medical alcohol;
food coloring;
measuring capacity;
pipette;
a thin tube made of glass or plastic;
vegetable oil;
plasticine or molding clay;
ruler;
marker with a thin rod;
white paper with a dense structure;
Scotch;
cold and hot water;
a conventional thermometer, which will be required for calibration.

Homemade thermometer

Manufacturing scheme homemade device looks like that:

into container ( plastic bottle) you should pour water and medical alcohol in proportions 1:1.
Then add a few drops of food coloring to the solution. It should be added with a pipette.
The dye is required for easy detection of temperature changes.
It is important that the solution fills the bottle to the very brim.
After that, a plastic or glass tube is inserted into the bottle. It must be inserted carefully so that water does not spill out.
Lift the top of the straw over the neck so that it protrudes about 10 centimeters, the other end should not reach the bottom of the bottle.
We install the tube correctly and fix it with molding clay or plasticine.
The closure must be tight so that liquid cannot leak out of the container.
On the side of the tube, attach a strip of white thick paper. It must be placed on the back of the tube and attached with adhesive tape.
Paper is required to facilitate control of the liquid level in the tube. Also in the future it will be possible to put labels on it.
The measuring solution must also be added to the tube, it should be added using a pipette.
It is important to ensure that the liquid in the tube rises to a height of five centimeters above the neck of the bottle.
Next, you need to add a drop of vegetable oil to the tube. This must be done carefully, it is better to use a pipette.
Vegetable oil will prevent the measuring liquid from evaporating and increase the life of your homemade thermometer.

Trial

After complete assembly thermometer, it must be checked. To do this, you need to alternately lower it into bowls with cold and hot water. When placed in cold water the liquid level in the tube should decrease, in the hot - rise. If this happens, this means that the device is assembled correctly.

You can calibrate the product using a conventional thermometer. To do this, it should be brought to the paper, leaned slightly and marked with a marker. Calibration will help you use homemade device for measuring air or liquid temperature.

Difficult option - electronic thermometer

Device diagram

Deciphering the indicators of the scheme

If you are fond of technology, then you can make an electronic thermometer. But for it you will need to purchase special parts. For self-manufacturing a simple device with the following indicators is suitable:

temperature range from 0 to 99 degrees Celsius;
input power level 4.5-5V DC;
consumption current indicator - 20 mA.

Electronic thermometer board (wiring diagram).

To make an electronic device for measuring temperature, you will need to purchase a special board. If you want the readings to be clear and visible from afar, then it is better to use large and bright LED indicators. Correct connection and connection of external elements to the board is shown in the figure.

Board with external elements

If the thermometer will be used to measure the temperature outside, it must be mounted in a special box with a network adapter inside the apartment. The temperature sensor itself is connected using a flexible cable.

Flex circuit board

Advantages and disadvantages

The advantages of a self-made device include:

simple manufacturing;
can be made from cheap improvised materials, which is cost-effective;
no aggressive substances are required. As a measurement, a liquid of water and alcohol can be used;
easy application;
long service life.

But there are several disadvantages:

electronic versions have complex scheme manufacturing;
for products with an electronic or digital device, it is required to purchase special boards, circuits;
sometimes products may show inaccurate measurements.

Homemade thermometers are a great way to save money on a new instrument. A do-it-yourself device will last much longer than cheap measuring devices.

The period of senior preschool and primary school age is a favorable time for the formation of an idea of measurement. Children 5 - 8 years old learn about the appointment of various measuring instruments and devices (ruler, protractor, watch, scales, thermometer), actively master the methods of carrying out various measurements, consciously use concepts denoting units of measurement. Sometimes it is difficult to explain the principle of operation of a particular device, therefore, models come to the aid of parents and teachers that help the child understand how the measuring device works.

We will tell you step by step how to make a thermometer out of cardboard. Such a paper thermometer can be used in familiarization classes with others in kindergarten or in the lessons of mathematics and natural history in primary school schools while running . Also, a do-it-yourself cardboard thermometer can be hung on the wall in the children's room. Thanks to the model, it will be easier for the child to understand what zero is, what negative and positive numbers mean, to establish a connection between the readings of the device and changes in nature or in bodily sensations.

We will need:

light cardboard or semi-cardboard;
thick threads of red and white color;
a needle with a large eye;
ruler,
automatic pen or bright felt-tip pen;
pencil.

Completing of the work:

After explaining to the child how a device that measures air temperature works, you can play with him a game with the movement of a two-color thread “What happens?” The red indicator is at a minus mark - the child can list what is happening in nature: "It's cold outside, it's snowing, puddles are covered with ice, people put on warm jackets, hats, mittens," etc. If the indicator is at a positive temperature, the child remembers what happens in nature when it is warm.

For children's "House" and "Hospital" you can make a medical thermometer out of cardboard with your own hands.

How to make a thermometer out of cardboard?

Such models, which contribute to the mental development of the child, are very good to do, involving the children themselves in the manufacture. crafts made with my own hands, especially delight little craftsmen and encourage them to treat the objective world more responsibly and carefully.

Suggested for self assembly digital temperature meter allows you to measure the temperature in real time in the range from zero to 99 degrees Celsius. The project was developed on the basis of PIC16F1825 microcontroller, CAT4016 driver for LED display, temperature sensor DS18200 and two 7-segment common anode LED indicators. This handy little thermometer draws fairly little current and can be powered by a 4.5 volt battery made up of 3 AA cells. The brightness of the display can be changed by changing the value of resistor R1.

Electronic thermometer - circuit diagram

Characteristics of the electronic thermometer

Temperature range from 00 to 99 degrees
Input power 4.5 - 5V DC
Current consumption 20 mA

Despite the fact that now there is a trend to use more economical LCDs as a display, it makes sense to put large bright LED indicators in this device so that the readings can be seen from afar and even in the dark. The connection diagram and connection of external elements to the board is shown above.

If you plan to use it as an outdoor thermometer, the device itself is mounted in a box with a network adapter inside the apartment, and the DS18200 temperature sensor is connected with a flexible cable. If it is not possible to search for controllers, you can assemble them on ordinary microcircuits. Firmware for the microcontroller, original article in English and drawing printed circuit board can