AME Unit 9 Q1

A PT100 probe is a type of Resistance Temperature Detector (RTD) that uses platinum as its sensing element.

1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology

• PT stands for Platinum.   1. What Is A Pt100 Sensor? [Complete Guide] peaksensors.com
• 100 indicates its nominal resistance of 100 ohms at 0 degrees Celsius.   1. What Is A Pt100 Sensor? [Complete Guide] peaksensors.com

How it Works:

• The probe’s platinum resistance changes predictably with temperature fluctuations.   1. The Pt100 Probe | G.Sensor Italy www.thermocouple-pt100atex.com
• This change in resistance is measured and converted into a temperature reading.   1. Resistance thermometers: The most important information incl. video – JUMO en.jumo.de

Key Characteristics:

• High Accuracy: Offers precise temperature measurements.   1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology www.picotech.com
• Wide Temperature Range: Can measure temperatures from -200°C to 850°C.   1. Introduction to Pt100 RTD Temperature Sensors – Omega Engineering www.omega.com
• Stability: Exhibits excellent stability over time.   1. What is a PT100 Sensor? – YouTube www.youtube.com
• Linearity: The relationship between resistance and temperature is relatively linear.   1. What is a PT100 Sensor? – YouTube www.youtube.com

Common Applications:

• Industrial process control
• HVAC systems
• Automotive industry
• Scientific research
• Food processing

In essence, a PT100 probe is a reliable and accurate tool for monitoring and controlling temperature in various applications.  

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PT100 probe

A PT100 probe operates on the principle of resistance change with temperature.  

1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology

• Resistance Temperature Detector (RTD): As the name suggests, a PT100 is a type of RTD.   1. Introduction to Pt100 RTD Temperature Sensors – Omega Engineering www.omega.com
• Platinum Element: The sensing element in a PT100 is pure platinum, known for its stable and predictable resistance changes with temperature.   1. What Is A Pt100 Sensor? [Complete Guide] peaksensors.com
• Resistance-Temperature Relationship: When the temperature of the platinum element increases, its electrical resistance also increases. This relationship is highly linear over a wide temperature range.   1. What is the effect of temperature on the resistance of a metal? The resistance of a platinum resistances thermometer 0^oC temperature is 3.0Omega and 100^oC it is 3.75Omega. Its resistance an unknown temperature is 3.15Omega. Find the value of the unknown temperature. www.toppr.com
• Measurement: The change in resistance is measured using a Wheatstone bridge or similar circuit. By precisely determining the resistance, the corresponding temperature can be calculated using calibrated tables or formulas.

Key Points:

• The resistance change is very small, requiring precise measurement techniques.   1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology www.picotech.com
• The relationship between resistance and temperature is highly repeatable and accurate.
• PT100 probes offer a wide measurement range and good stability.   1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology www.picotech.com

By accurately measuring the change in resistance of the platinum element, the PT100 probe provides a reliable and precise indication of temperature.

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PT100 probe and its components

PT100 probes are widely used in marine applications due to their accuracy, reliability, and wide temperature measurement range. Some common applications include:  

1. Temperature sensors approved for marine applications – Danfoss

Engine Room Monitoring

• Engine coolant temperature: Monitors engine operating conditions and prevents overheating.
• Lube oil temperature: Ensures optimal engine performance and prevents damage.
• Fuel oil temperature: Controls fuel viscosity and combustion efficiency.
• Exhaust gas temperature: Monitors engine performance and emissions.
• Turbocharger inlet and outlet temperatures: Optimizes turbocharger efficiency.

Cargo and Ballast Systems

• Tank temperature: Monitors product temperature for quality control and safety.
• Cargo heating/cooling: Regulates temperature for optimal cargo condition.
• Ballast water temperature: Monitors water temperature for environmental regulations.

HVAC Systems

• Air and water temperature: Controls climate conditions for passenger comfort and equipment protection.

Other Applications

• Refrigeration systems: Monitors evaporator and condenser temperatures.
• Steering gear systems: Monitors hydraulic oil temperature.
• Bilge water temperature: Monitors environmental conditions.

By accurately measuring temperatures in various systems, PT100 probes contribute to the efficient operation, safety, and maintenance of marine vessels.

A PT100 probe is typically constructed in one of two primary ways:

1. Wirewound Construction

• Platinum Wire: A thin platinum wire is wound around a ceramic or glass core.   1. Wire-Wound vs. Thin-Film Resistance Temperature Detector: Which Is Better? – WIKA blog blog.wika.us
• Support Structure: This assembly is often encased in a protective sheath to provide structural support and protection.   1. Pt100 Sensor Explained | Working Principles – RealPars www.realpars.com
• Lead Wires: Fine wires are attached to the platinum winding to connect it to the measurement circuitry.

2. Thin Film Construction

• Ceramic Substrate: A thin layer of platinum is deposited onto a ceramic substrate.   1. What is a Pt100 Temperature Sensor Working Principle? – Process Parameters Ltd www.processparameters.co.uk
• Pattern Formation: The platinum layer is patterned into a specific design to achieve the desired resistance.
• Protection: The element is encapsulated within a protective housing.

Why PT100?

• Platinum: The name “PT100” indicates that the sensing element is made of platinum (Pt).   1. What is a Pt100 Temperature Sensor Working Principle? – Process Parameters Ltd www.processparameters.co.uk
• 100 Ohms: The numerical value “100” signifies that the probe has a resistance of 100 ohms at 0 degrees Celsius. This standardized resistance value allows for easy comparison and calibration.   1. PT100 sensors (Platinum Resistance Thermometers RTD sensors) – Pico Technology www.picotech.com

By carefully controlling the purity and dimensions of the platinum element, manufacturers can achieve the high accuracy and stability required for temperature measurement.

The number of wires in a PT100 probe is directly related to the accuracy and precision of the temperature measurement.

1. Pt1000 and Pt100 wiring – 2-, 3- or 4-wire? – Automated measurement and sensor technology for the industrial sector

Three-Wire PT100

• Compensation for Lead Resistance: The most common configuration, a three-wire PT100 helps to compensate for the resistance of the connecting wires.   1. Pt100 in 2-, 3- or 4-wire connection? – WIKA blog blog.wika.com
• How it works: One wire is connected to the center of the platinum element, while the other two are connected to the ends. By measuring the resistance between different combinations of these wires, the influence of the lead wire resistance can be minimized.

Four-Wire PT100

• Highest Accuracy: A four-wire PT100 offers the highest level of accuracy by completely eliminating the influence of lead wire resistance.   1. Can a High Precision RTD Temperature Measurement System (±0.15°C) Be Designed Without the Need for Calibration? | Analog Devices www.analog.com
• How it works: Two wires are used for supplying current to the PT100, while the other two are used for measuring the voltage drop across the element. This allows for a direct measurement of the platinum resistance without any interference from the lead wires.

In summary:

• Three-wire PT100: Offers good accuracy and is widely used in many applications.   1. Pt100 Wiring for your Industrial Temperature Sensors – Process Parameters Ltd www.processparameters.co.uk
• Four-wire PT100: Provides the highest accuracy but requires more complex wiring and instrumentation.   1. Pt100 in 2-, 3- or 4-wire connection? – WIKA blog blog.wika.com

The choice between a three-wire and four-wire PT100 depends on the required accuracy of the temperature measurement and the specific application.