The KY-013 Analog Temperature Sensor module is a sensor Based on the thermistor's resistance on the board, it can calculate the ambient temperature it has an operating Voltage of 5V and the temperature measurement range is from -55°C to 125°C [-67°F to 257°F] with measurement Accuracy of ±0.5°C. compatible with well-liked electronic hardware platforms like the Arduino and ESP32. 

Package Includes:

• 1x NTC Temperature Analog Sensor Module KY-013
  
  

Features:

• Thermistor cost is economical
• Provided with lacquer-coated thermistor disk
• Copper leads have a coating of tin.
• Onboard resistors, no need for external components
• Good stability, and durability in the environment
• Provide high accuracy in resistance and B-constant

Description:

The KY-013 Analog Temperature Sensor module is a sensor Based on the thermistor's resistance on the board, it can calculate the ambient temperature it has an operating Voltage of 5V and the temperature measurement range is from -55°C to 125°C [-67°F to 257°F] with measurement Accuracy of ±0.5°C. compatible with well-liked electronic hardware platforms like the Arduino and ESP32. Thermistors are straightforward, reasonably priced, and precise components that make obtaining temperature information for your projects simple. The use of thermistors would be best in remote weather stations, home automation systems, and equipment control and protection circuits, to name a few. The code is relatively straightforward because they are analog sensors as opposed to digital temperature sensors, which call for complex libraries and a lot of code.

Principle of Work:

The resistance of thermometers, which are variable resistors, varies with temperature. They are categorized based on how they react to temperature changes in terms of resistance. Resistance decreases as temperature rises in thermistors with a negative temperature coefficient (NTC). The most popular thermistors are NTC ones. NTC thermistors are created by heating and compressing a semiconducting material (like metal oxide or ceramic) to create a temperature-sensitive conducting material. Charge carriers in the conducting material enable current to pass through it. The semiconducting material releases more charge carriers when the temperature is elevated. Electrons are the charge carriers in ferric oxide-based NTC thermistors. Electron holes serve as the charge carriers in nickel oxide NTC thermistors.

To measure the resistance of the NTC Thermistor, first, we will measure the voltage from the voltage divider which is the output or s pi. And the voltage divider equation is as follows.
Vout = Vin*[R2/(R1+R2)]
Since we know Vin, R1, and Vout we can calculate the value of the NTC thermistor R2 with the following equation

R2=(Vout*R1) / (Vin-Vout)

Pinout of the Board:

KY-013	Description
S	Analog signal out
middle	5V
–	GND

Applications:

1. Domestic application – Fridges, freezers, cookers and deep-fat fryers, etc.
2. Industrial, Telecommunication application - Process control, heating and ventilation, air conditioning, fire alarms, temperature protection in battery management/charging systems, Video and audio equipment, mobile phones, and camcorders, etc.
3. Automotive application - Inlet air-temperature control, engine temperature control, airbag electronic systems, etc.
4. Thermistors can be used for temperature compensation, temperature measurement, and temperature control.

Circuit:

S pin to pin A0 on Arduino

- pin to GND on Arduino 

middle pin to 5V on Arduino

Library: 

you don't need any library to work with this sensor.

Code:

This code is going to print the Temperature Sensor Module on the Serial Monitor.

#define ntc_pin A0         // Pin,to which the voltage divider is connected
#define vd_power_pin 2        // 5V for the voltage divider
#define nominal_resistance 10000       //Nominal resistance at 25⁰C
#define nominal_temeprature 25   // temperature for nominal resistance (almost always 25⁰ C)
#define samplingrate 5    // Number of samples
#define beta 3950  // The beta coefficient or the B value of the thermistor (usually 3000-4000) check the datasheet for the accurate value.
#define Rref 10000   //Value of  resistor used for the voltage divider
int samples = 0;   //array to store the samples
void setup(void) {
  pinMode(vd_power_pin, OUTPUT);
  Serial.begin(9600);   //initialize serial communication at a baud rate of 9600
}
void loop(void) {
  uint8_t i;
  float average;
  samples = 0;
  // take voltage readings from the voltage divider
  digitalWrite(vd_power_pin, HIGH);
  for (i = 0; i < samplingrate; i++) {
    samples += analogRead(ntc_pin);
    delay(10);
  }
  digitalWrite(vd_power_pin, LOW);
  average = 0;
  average = samples / samplingrate;
  Serial.println("\n \n");
  Serial.print("ADC readings ");
  Serial.println(average);
  // Calculate NTC resistance
  average = 1023 / average - 1;
  average = Rref / average;
  Serial.print("Thermistor resistance ");
  Serial.println(average);
  float temperature;
  temperature = average / nominal_resistance;     // (R/Ro)
  temperature = log(temperature);                  // ln(R/Ro)
  temperature /= beta;                   // 1/B * ln(R/Ro)
  temperature += 1.0 / (nominal_temeprature + 273.15); // + (1/To)
  temperature = 1.0 / temperature;                 // Invert
  temperature -= 273.15;                         // convert absolute temp to C
  Serial.print("Temperature ");
  Serial.print(temperature);
  Serial.println(" *C");
  delay(2000);
}

Technical Details:

• Resistance at 25 degrees C: 10K +- 1%
• B-value (material constant) = 3950+- 1%
• Dissipation factor (loss-rate of energy of a mode of oscillation) δ th = (in the air)approx.7.5mW/K
• Thermal cooling time constant <= (in the air) 20 seconds
• Thermistor temperature range from -55 °C to 125 °C
• Operating Voltage: 5v

Resources:

Datasheet

Tutorial

 

Comparisons:
thermometers are very cheap, but imprecise, and their resistance changes with temperature in a non-linear manner, determining the temperature requires a little "work" on your software's part. Although more expensive, active devices like the LM35 are more accurate and provide a linear voltage-vs-temperature characteristic, making it simpler to determine the temperature. The LM35 is calibrated. The thermistor has to be calibrated against some known-good temperature standards to provide a temperature measurement in a range from -55 °C to 125 °C. The LM35 device does not require any external calibration or trimming to provide typical accuracies of ±¼°C at room temperature and ±¾ °Cover a full −55°C to 150°C temperature range.