Different Types of Weather Instruments

Introduction to Weather Instruments

The innovative non-moving part sensors are pushing the old mechanical sensors to the back. Modern ultrasonic wind speed sensors can detect wind gusts of up to 70 m/s (approximately 252 km/h or 157 mph) with a response time of 3 seconds. In comparison, the mechanical cup anemometers require 6 seconds to respond. Moreover, the traditional cup anemometer has moving parts that are prone to wear and tear. We can clearly see from this evolution of sensors that the landscape of weather instruments is changing.

Wind speed is just one of many parameters for weather prediction and reporting. The latest technology that collects weather data is ultrasonic weather stations. The use of simple sound waves traveling back and forth within the air medium allows these sensors to detect multiple parameters. The time taken by a soundwave of a particular wavelength represents the respective parameter of the wind.

In this article, we will discover all the common weather instruments you need to know for accurate weather monitoring and prediction. We will discuss the common and specialized instruments used to measure wind speed, temperature, atmospheric pressure, humidity, precipitation, and solar radiation.

Applications of Weather Instruments

It's important to understand the various applications of weather instruments to fully appreciate their significance. Every field will require analysis of one or more weather parameters. Here are some applications of weather instruments:

• Meteorology: For the accurate prediction of storms and analysis of atmospheric conditions, weather instruments are essential. These data points can help analyze long-term climate patterns.
• Agriculture: Farmers use weather instruments to analyze local conditions and make informed decisions. Based on the data, they can determine when to plant crops and protect livestock from extreme weather.
• Aviation: When the whole field is based around aerodynamics, you need accurate wind readings and atmospheric conditions to take a flight. The aviation industry rigorously monitors atmospheric conditions using weather instruments.
• Power Plants: In some plants, there is always going to be a discharge from a stack. Monitoring atmospheric conditions to time the releases is key to ensuring compliance with effluent discharge regulations.
• Construction: It's vital to decide activities based on wind and rain conditions. Protecting property, material, and workers from extreme weather is key to a successful project.
• Renewable Energy: Solar panels, wind turbines, tidal energy converters all require weather instruments to predict energy production and ensure a proper energy mix.

Common Weather Instruments

♦ Thermometer

Temperature is the key parameter in weather studies. It determines everything from the state of water to atmospheric pressure and wind patterns. Instruments that measure temperature work on the principle of thermal expansion or electrical resistance. However, there are five types of temperature-measuring weather instruments:

• Mercury/Alcohol (Traditional): It utilizes the expansion as a gauge to measure temperature. The process is analog and may require sophisticated technology to convert into modern digital form.
• Platinum Resistance (PRT): It utilizes the resistance change of platinum material with temperature to measure atmospheric temperature. It produces repeatable results with a -200 °C to 600 °C or higher range.
• Thermistors: These utilize the semiconductor material property of a decrease in resistance as temperature increases.
• Thermocouples (Digital): Using the Seebeck effect, two dissimilar metal wires are joined together at a junction exposed to temperature changes. A voltage difference between the two wires represents the temperature change. They come in different types.
• Semiconductors: The forward voltage of the PN junction changes as the temperature changes.

Best Weather Instrument for Temperature:

RIKA PT100 (PRT Type) integrated into the RK900-10 weather station.

Accuracy: ±0.2°C

Resolution: 0.1°C

Range: -40°C to +80°C Standard (Extendable -200°C to +600°C)

♦ Barometer

Measuring pressure is key to predicting weather and cloud formations. Regions of low and high pressure are critical data points for algorithms that enable weather prediction. Here are some types used in weather instruments:

• Aneroid Barometers (Mechanical/Electronic): These are sealed metal capsules that expand or contract in response to the pressure around them. Its movement is converted into an electrical signal measuring pressure.
• Digital/Capacitive Barometers: These devices utilize the change in capacitance between two plates when pressure is applied to generate a pressure signal.  
• Piezoresistive Barometers: Strain gauges that generate a signal upon contraction and expansion are mounted on a diaphragm that moves in response to pressure changes.

Best Weather Instrument for Pressure

Digital/Capacitive Barometer, integrated into the RIKA RK900-12 ultrasonic automatic weather station.

Accuracy: ±50-100 Pa

Resolution: 10 Pa

Range: 30,000-110,000 Pa

♦ Hygrometer

Hygrometers measure humidity in the air. Humidity levels also help predict weather conditions. It is the measurement of water vapor in the air. It directly affects the comfort level for humans.

• Capacitive Hygrometers: The Dielectric material between capacitors causes a change in capacitance with a change in humidity levels.
• Resistive Hygrometers: These measure the change in resistance of the substrate (e.g., ceramic or polymer) when exposed to moisture.

Best Weather Instrument for Humidity

RIKA RK33-02 Capacitive Meter In RK900-12 Ultrasonic Automatic Weather Station

Accuracy: ±3% RH (0-80% RH), ±5% RH (80-100% RH)

Resolution: 1% RH

Range: 0-100% RH

♦ Anemometer

Anemometers measure wind speed. Measuring wind speed is essential in aviation, power plants, agriculture, renewable energy, and other sectors. Here are its types:

• Cup Anemometers (Mechanical/Rotational): These devices utilize three or four hemispherical cups connected to a shaft. Air rotates the shaft, which induces a signal proportional to speed.
• Ultrasonic Anemometers (Contactless/Acoustic): Ultrasonic pulses travel between transducers. The transit time changes with wind speed (time-of-flight principle). There are no moving parts, leading to a highly responsive and immune to mechanical failure wind speed sensor.

Best Weather Instrument for Wind Speed

RIKA RK120-01 Ultrasonic Wind Sensor in RK900-12 Ultrasonic Automatic Weather Station

Accuracy: ±3%

Resolution: 0.1 m/s

Wind Speed: 0-60 m/s

♦ Rain Gauge

The amount of rain that happens can help farmers plan a watering schedule and crop conditions. Moreover, city planners can monitor the condition of and open spillways as needed, and set water diversions as required. It is a key instrument in weather condition monitoring.

• Tipping Bucket Rain Gauges: The working mechanism is simple; a small bucket tips (e.g., every 0.2 mm) to empty. It provides the value in mm/m² (millimeters of rainwater collection over a square meter of area). Every tip is recorded, generating a signal.
• Radar Rainfall Sensors: Utilizing Doppler and acoustic principles, these sensors detect precipitation remotely without the need for physical collection. It can detect drop size, velocity, and intensity.
• Optical/Acoustic Rain Sensors: Using light interruption (optical) or sound waves (acoustic) to detect raindrops or snow, often paired with tipping buckets for qualitative/quantitative data.

Best Weather Instrument for Rain

RIKA RK400-01 Metal Tipping Bucket Rainfall Sensor

Accuracy: ±4% or ±2 mm

Resolution: 0.2 mm

Range: 0-999.9 mm

Rate: 0-200 mm/hr

♦ Wind Direction

Finding the direction of the wind is vital in many fields, similar to the use of anemometers. They are usually utilized in conjunction with each other to get the complete picture of wind conditions. There are traditional and modern methods to detect wind direction:

• Mechanical Wind Vanes: These devices use a piece of metal or a vane that aligns itself with the wind direction while simultaneously rotating a shaft that generates a directional signal. The more advanced form of these wind vanes utilizes carbon fiber material, which offers a lower response time and quicker adjustments.
• Ultrasonic Wind Direction Gauges: Similar to anemometers, these gauges utilize ultrasonic sound that travels from the transmitter to the receiver. Using multiple of these in different directions and analyzing their time-of-flight can unlock wind direction.

Special Weather Instruments

★ Radiosonde

These are used to monitor upper atmospheric conditions. To reach such heights, it can use a helium or hydrogen-filled weather balloon. These can ascend at ~300 meters/minute to altitudes exceeding 35 km. These are battery-powered and lightweight. It can measure pressure, temperature, relative humidity (RH), altitude (via GPS), and wind speed/direction (in rawinsonde mode).

Best Radiosonde

RK-RADIO-01 (standalone radiosonde package) or integrated in RK900-10 for upper-air extensions.

★ Weather Radar

Using large-scale systems, such as Doppler networks, employed by national meteorological agencies, can be expensive. For most users, a 24G millimeter-wave radar sensor is sufficient for precise, localized rainfall monitoring. It uses short pulses to detect precipitation particles, measuring intensity, accumulation, and even drop velocity via Doppler shifts. There are no mechanical parts, which makes it feasible for long-term projects.

Best Weather Radar

Millimeter-Wave Radar Precipitation Sensors (24G Frequency) in RK900-10

Latest Innovations in Weather Instruments

The latest innovation in weather instruments is the integration of advanced sensors and gauges with AI software. It can provide real-time analytics and discover intricate details that an analyzer can otherwise miss. AI technology can analyze all the data from multiple sensors and combine them to provide statistical insights.

Moreover, the use of radar rainfall sensors in combination with a solar-powered system is revolutionizing data collection in remote areas. Particularly, the ultrasonic weather stations are compact, accurate, and ultra-low maintenance.

If you are looking for the most advanced weather instruments, then visit the RIKA website. They offer options ranging from traditional to modern ultrasonic weather stations that can provide multiple weather parameters simultaneously. These stations utilize RS-485/Modbus-RTU, 4-20 mA Analog Output, 4G/LTE Cellular, WiFi (2.4 GHz), or LoRa (Long Range) to transmit data.

Frequently Asked Questions (FAQs)

Q: What makes Rika's ultrasonic anemometers innovative?

They have no moving parts, which makes them ultra-low maintenance. Due to their working mechanism, which utilizes ultrasonic waves and the time-of-flight principle, they can measure multiple parameters in the air, including wind speed, direction, humidity, and rain.

Q: Can you set up a remote weather station?

Yes, Rika’s RK900-12 ultrasonic station, powered by solar panels and batteries, enables off-grid operation. It uses ultrasonic wind sensors, a tipping-bucket rain gauge, and 4G/LTE for real-time data transmission. IP65-rated, it operates in temperatures ranging from -40°C to +80°C, making it ideal for remote meteorology and agriculture applications.

Q: What is the size and weight of an overall weather station?

The answer depends on the type of weather station. Modern ultrasonic weather stations, such as the Rika’s RK900-12 ultrasonic weather station measure ~30 cm (height) x 20 cm (diameter) and weigh ~2-3 kg. Including sensors (ultrasonic anemometer, tipping bucket), it’s portable, IP65-rated, and solar-compatible for remote meteorology and agriculture, with 4G/WiFi data delivery.