” LORA TEMPERATURE SENSOR “

A temperature sensor is an electronic device that measures the temperature of its environment and converts the input data into electronic data to record, monitor, or signal temperature changes.

LoRa is a modulation technique for specific wireless spectrum.

__LORAWAN__

LoRaWAN sensor that measures temperature and humidity, with an incredible maintenance free lifetime of 10 years at a 5-minute measurement interval. Easy to use, configurable over the air and stylish in design to fit into indoor spaces.

Uses :

•  Heat allocation
• Indoor climate control

LoRaWAN sensors are IoT devices created to function on LoRaWAN networks. These networks are particularly useful for wireless sensors due to their ability to transfer data across long distances. They also have high-performing link margins that reach signals below the radio frequency (RF) noise floor.

__ WIRELESS TEMPERATURE SENSOR __

( NO-PROBE TEMPERATURE SENSOR)

The wireless no-probe temp sensor measures temperature of the air surrounding the sensor without any external probes such as a thermocouple or thermistor.

If the temperature rises above or falls below the configured thresholds, an alert is sent over the wireless network.

__ACCURACY__

The accuracy of the sensor is the maximum difference that will exist between the actual value (which must be measured by a primary or good secondary standard) and the indicated value at the output of the sensor.

Again, the accuracy can be expressed either as a percentage of full scale or in absolute terms.

     RTDs have typically an accuracy of 0.1°C, compared to 1°C for most. However, some thermocouple models can match RTD accuracy.

// FACTORS //

The many factors that can affect sensor accuracy include linearity, repeatability or stability.

• Linearity :

” An ideal sensor would have a perfectly linear response: a unit change in temperature would result in a unit change in voltage output across the entire temperature range of the sensor.”

{ In reality, however, no sensor is perfectly linear.}

• Repeatability :

” Repeatability is defined as how constant a sensor is against itself. It can be used to describe the ability of a sensor to provide the same result under the same circumstances over and over again.”

For instance, the temperature sensor shown here has a repeatability of plus or minus 1 LSB (Least Significant Bit).&?

• Stability : 

” The stability of a Lora temperature sensor is an indication of its ability to maintain a consistent output at a given temperature.”

Material plays a key role in the stability of a given sensor. RTDs are often constructed of platinum for this reason as well as to ensure low reactivity.

// VARIATIONS //

Repeatability and reproducibility are two aspects of precision. Describing the minimum variability of precision, repeatability identifies variations that occur when conditions are constant and the same operator uses the same instrument within a short period of time.

__TYPES__

The four most common types of temperature sensors, ranging in responsiveness and accuracy from high to low are:

• Negative Temperature Coefficient (NTC) Thermistors.

• Resistance Temperature Detectors (RTDs)

• Thermocouples

• Semiconductor-Based Sensors

__ADVANTAGES__

• Temperature sensors are low-cost, precise, and extremely reliable in repeated experiments.
• They are desirable for both embedded and surface mount applications.
• They have a faster response time because of the lower thermal mass.
• The vibrating wire type is normally full-interchangeable.

__ DISADVANTAGES__

• RTD is non linearity. Lower absolute resistance, current source needed.
• They have least stability. Its cost is expensive.
• It has low voltage. RTD’s is less rugged compare to thermocouples etc.
• The reference is needed, least sensitivity.

__ WORKING PROCESS__

LoRa works by moving an RF tone around over time in a very linear way. The  graph shows the chirps in a reverse waterfall— the newest data is at the top is called an up chirp. The frequency of the tone is increasing over time.

For communication between two LoRa Module, you need to have LoRa library. To get the LoRa Library go to library manager and search for LoRa and install it. Once the library is installed you can upload the transmitter and receiver code and learn about Sending Sensor Data Wirelessly with LoRa SX1278 & Arduino.

// LORA MODULE //

MultiTech LoRa modules are secure, regulatory-certified, Arm® Mbed™ programmable, low-power RF modules, providing long-range, low bit rate IoT data connectivity to sensors and actuators.

// LORA GATEWAY //

LoRa gateways are radio modules that serve as communication devices within a LoRa network between end-devices and a LoRaWAN network server (LNS). A LoRa gateway is mostly used to transmit sensor data from an electrical device to the cloud.

// RANGE //

The name, LoRa, is a reference to the extremely long-range data links that this technology enables. Created by Semtech to standardize LPWANs, LoRa provides for long-range communications: up to three miles (five kilometers) in urban areas, and up to 10 miles (15 kilometers) or more in rural areas (line of sight).

// FREQUENCY //

LoRa transmits over license-free megahertz radio frequency bands: 169 MHz, 433 MHz (Asia), 868 MHz (Europe) and 915 MHz (North America).

__APPLICATIONS__

• LORA SPY Long Range Connected Sensors
• OY1110 LoRaWAN Temperature & Humidity Sensor

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