Immersion Temperature Sensor

Description

The Ace Instruments immersion type temperature sensors feature options of RTD Pt100, RTD Pt1000, or NTC thermistors. Designed with versatility in mind, the AI-200-T series features optional stainless steel thermowells, allowing users to measure water or fluid temperatures in HVAC systems or any pipeline application with selectable thermowell length to ensure accurate temperature readings. Each probe provides superior heat transmission, quick reaction times, and the thermowells offer protection from moisture.

Pt1000 Sensing Technology

Platinum resistance thermometers change resistance predictably with temperature. The Pt1000 has a resistance of exactly 1,000 Ω at 0°C, increasing approximately 3.85 Ω per degree Celsius. This predictable, repeatable relationship makes it the preferred sensor for precision temperature measurement. Across the HVAC temperature range of -40°C to +150°C, Pt1000 resistance thermometry provides better accuracy and long-term stability than thermocouple sensor types, making it well suited to applications where precise, drift-free readings matter over years of continuous operation.

HVAC Water Circuit Applications

Accurate fluid temperature measurement underpins control decisions throughout an HVAC system, from confirming chilled water is reaching design temperature, to verifying hot water circuits are delivering the heat output a building needs, to tracking condenser or cooling tower water performance. Because the sensor is immersed directly into the fluid rather than measuring pipe surface or ambient air temperature, it captures true process temperature, giving control systems the accurate input needed to manage pumps, valves, and heating or cooling equipment effectively.

Installation Guide

The probe is installed through a thermowell (recommended for applications requiring sensor removal without draining the system) or via direct insertion into the pipework. Correct fitting selection depends on system pressure, fluid type, and whether maintenance access is needed without shutting down flow. The sensing tip should be positioned within the main flow of the fluid stream, avoiding installation too close to elbows, valves, or other turbulence sources, to ensure the reading reflects actual bulk fluid temperature.

Accuracy & Calibration

Pt1000 elements offer high inherent accuracy and stability, with minimal drift over the sensor's operating life compared to thermocouple alternatives. Periodic verification against a calibrated reference is still recommended for applications with strict process or compliance requirements, ensuring the sensor continues to deliver dependable, repeatable readings throughout its service life.

Applications

• Data Center Cooling Systems
  In IT infrastructure environments like data centers, server rooms, and other critical applications, the Ace Instruments immersion temperature series supports maintenance of ideal temperature. In IT infrastructure & data center cooling systems, deviation of temperature by a small degree creates a significant energy cost. The AI-200-T series supports facility managers in achieving the ideal environmental condition with high accuracy options including RTD Pt1000 (0.1 degree C accuracy), NTC 10k (0.1 degree C accuracy).
  
  
• Chilled & Hot Water Lines in Water Distribution Loops
  The AI-200-T series directly measures the liquid’s temperature with seamless data transmission to building HVAC and automation systems. The immersion temperature sensor uses high accuracy RTDs - Pt100, Pt1000 respectively as well as thermistors - NTC 10k. With the thermowell, the immersion temperature sensor is waterproof, allowing for easy installation and wiring. This makes temperature monitoring and control in chilled & hot water lines easy for users.
• Aggressive/Viscous Media Temperature Process Control
  The AI-200-T immersion temperature sensor is the ideal companion in all process applications where pressure, velocity or viscous, abrasive and corrosive materials are present individually or in combination. A temperature sensing element protected with an Ace Instruments thermowell will protect the temperature instrument from possible damage resulting from these process variables.
• Hygienic Food / Pharma Applications
  The AI-200-T series comes with an option of SS316 food grade stainless steel immersion sensor with thermowell. This makes it the ideal partner for food & beverage, life sciences, and pharmaceutical applications where the sensor comes into contact with aseptic processes.
  
  
• Building Automation Systems
  The resistance output of the immersion temperature sensors can be taken directly to
  
  • DDC controllers
  • Energy metering systems
  • VAVs
  • Chiller/Boiler controllers

This enables users to get real time datapoints and ensure process optimization for their application.

‍Features

• Range of Outputs
  The Ace Instruments immersion temperature series features a range of sensing elements for users to choose: NTC 10k, Pt1000, Pt100. Users can select the sensing element best suited to their application for compliance across pharma, HVAC, and data centers.
• Stainless Steel Thermowell
  Each immersion sensor has an option of supply with a SS304 thermowell, customized to offer optimal protection to the AI-200 series immersion temperature sensors. We recommend that you only use Ace Instruments thermowells su

• Customizable Solution for Process Compliance Across Industries
  We strive to offer users control over their process, and the same applies to the AI-200/200T series. We offer the below customizations for optimal compliance with your unique requirements.
  
  
  • Customizable Immersion Sensor Length: Choose between 50 mm, 75, mm, 100 mm for the length of the immersion sensor. Custom thermowell available on request.
    
  • Thread Type: The AI-200/200T series is built to suit your process connections, with option of ½” BSP, ½” NPT & ¼” BSP. ‍
  • Cable Length: Customize the immersion sensor cable length upto 3 m, with options of 1 meter, 2 meters and 3 meters.

Standards ‍

The AI-200 Series of immersion temperature transmitters enables users to comply with standards from leading international organizations with oversight over critical processes, including pharma manufacturing, medical devices, food and HVAC applications.

• U.S. Food & Drug Administration (USFDA): The FDA recommends usage of immersion sensors in processes across Food, Drugs, Biologics, Medical Devices and Diagnostic Products.
  
  
• EU Good Manufacturing Practices (GMP): The EU GMP recommends usage of qualified temperature monitoring devices. The AI-200 Series with RTD Pt1000 & RTD Pt100 is suited for use in GMP areas and processes.
  
  
• American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE): ASHRAE Guideline 22 emphasizes on the utility of temperature sensors in chilled water lines & provides a comprehensive framework for turning raw data from a chilled water plant into actionable information for improving and maintaining its energy efficiency.

Frequently Asked Questions (FAQs)

1. What is the AI-200/200T Immersion Temperature Sensor?

The AI-200/200T is an immersion temperature sensor designed to accurately measure the temperature of liquids flowing through pipes, tanks, and vessels. It is widely used in HVAC systems, chilled water lines, hot water systems, boilers, heat exchangers, and industrial process applications where continuous temperature monitoring is essential.

2. What does the AI-200/200T measure?

The AI-200/200T measures the temperature of liquids such as:

• Chilled water
• Hot water
• Heating water
• Process water
• Glycol solutions
• Industrial fluids

The measured temperature can be used by Building Management Systems (BMS), PLCs, or HVAC controllers for monitoring and process control.

3. What is a Pt1000 sensor and how does it work?

A Pt1000 is a platinum resistance temperature sensor that measures temperature by detecting changes in electrical resistance.

The "Pt" indicates that the sensing element is made from platinum, while "1000" means it has a resistance of 1,000 ohms at 0°C. As the temperature increases, the resistance changes in a precise and predictable manner, allowing highly accurate temperature measurement over a wide operating range.

Pt1000 sensors are known for their excellent accuracy, stability, and long service life, making them ideal for HVAC and industrial applications.

4. What is the difference between a thermocouple and a Pt1000 immersion probe?

Both devices measure temperature, but they operate differently.

A thermocouple generates a small electrical voltage that varies with temperature and is mainly used for extremely high-temperature applications, often above 1,000°C.

A Pt1000 sensor measures changes in electrical resistance and is better suited for temperatures typically encountered in HVAC and industrial systems, generally from -50°C to +200°C. It offers higher accuracy, better long-term stability, and simpler measurement electronics than most thermocouples.

5. How is the immersion probe installed in a pipe?

The probe is installed through a threaded fitting, such as G½ or G¾, that is welded or threaded into the pipe.

For accurate measurements, the sensing element should extend well into the flowing liquid. As a general guideline, the immersion length should be at least 50% to 75% of the pipe's internal diameter.

For hot, pressurized, or critical systems, the sensor is often installed inside a thermowell. A thermowell allows the sensor to be removed or replaced without draining the pipeline or interrupting system operation.

6. Where is the AI-200/200T commonly installed?

Typical applications include:

• Chilled water systems
• Hot water systems
• Air Handling Units (AHUs)
• Boilers
• Heat exchangers
• Cooling towers
• HVAC piping
• Industrial process pipelines
• District cooling systems
• Pharmaceutical process equipment
• Food processing plants

7. Why is liquid temperature monitoring important?

Monitoring liquid temperature helps maintain system efficiency, protect equipment, improve process control, reduce energy consumption, and ensure products are manufactured or stored under the correct environmental conditions.

Continuous temperature monitoring also helps identify system faults before they result in costly equipment failures.

8. Can the AI-200/200T be integrated with a Building Management System (BMS)?

Yes. The AI-200/200T is designed to work with temperature transmitters, HVAC controllers, PLCs, and Building Management Systems.

When connected to a suitable transmitter or controller, the measured temperature can be displayed, recorded, and used for automatic process control.

9. Is the AI-200/200T suitable for chilled and hot water systems?

Yes. The immersion sensor is suitable for both chilled water and hot water applications, making it an ideal choice for HVAC systems, district cooling, heating networks, and industrial process installations.

10. Can the sensor be used in industrial process applications?

Yes. The AI-200/200T is widely used in industrial applications where accurate liquid temperature monitoring is required, including manufacturing, food processing, pharmaceutical production, chemical processing, and water treatment systems.

11. Is the AI-200/200T suitable for continuous monitoring?

Yes. The sensor is designed for reliable 24×7 continuous operation and provides stable, repeatable temperature measurements over many years of service.

12. Does the sensor require calibration?

The AI-200/200T is factory calibrated before shipment. Periodic calibration or verification is recommended for applications requiring high measurement accuracy, especially in pharmaceutical manufacturing, laboratories, and regulated industrial processes.

13. Is installation easy?

Yes. The threaded mounting design allows quick installation into standard pipe fittings or thermowells. This makes the sensor suitable for both new installations and retrofit projects.

14. What are the advantages of using the AI-200/200T?

Key benefits include:

• Accurate liquid temperature measurement
• High-quality Pt1000 sensing element
• Excellent long-term stability
• Suitable for chilled and hot water systems
• Fast response time
• Easy installation
• Compatible with HVAC and industrial control systems
• Rugged construction for demanding environments

15. Who typically uses the AI-200/200T?

The AI-200/200T is widely used by:

• HVAC contractors
• Building automation integrators
• Facility managers
• Mechanical consultants
• Pharmaceutical manufacturers
• Food processing facilities
• Industrial maintenance engineers
• Boiler manufacturers
• Process engineers
• Water treatment plants

16. Why choose ACE Instruments?

ACE Instruments has over 30 years of experience in manufacturing temperature monitoring and environmental sensing solutions. Customers choose our products for their high measurement accuracy, reliable performance, industrial-grade construction, compatibility with BMS and HVAC systems, responsive technical support, and proven performance across commercial, industrial, pharmaceutical, and process applications.

17. How do I choose the right Immersion Temperature Sensor?

Choosing the right AI-200/200T depends on factors such as the process temperature range, pipe size, immersion length, mounting thread, sensor type, and application. Our application engineers can help you select the most suitable immersion temperature sensor for HVAC systems, chilled water networks, boilers, heat exchangers, industrial process lines, and other liquid temperature monitoring applications.

Specifications

Frequently Asked Questions (FAQs)

Q1. What sensing elements are available in the AI-200/200-T immersion temperature sensors?

A: The AI-200/200-T series offers RTD Pt100, RTD Pt1000, and NTC 10k thermistors, allowing users to select the sensing element best suited for their application requirements.

Q2. Do I need a thermowell with the immersion temperature sensor?

A: Yes, for most applications we recommend using Ace Instruments stainless steel thermowells. They protect the sensing element from moisture, pressure, and aggressive media, while ensuring accurate and reliable readings.

Q3. What thermowell options are available?

A: We offer SS304 standard thermowells and SS316 food-grade thermowells for hygienic applications. Custom thermowell lengths can also be provided on request.

Q4. What are the typical applications of the AI-200/200-T immersion temperature sensors?

A: These sensors are widely used in:

• Data center and IT cooling systems
• Chilled and hot water distribution loops
• Aggressive or viscous media process control
• Food, beverage, and pharmaceutical processes
• Building automation and HVAC systems

Q5. What cable lengths are available for the immersion sensors?

A: You can choose from 1 m, 2 m, or 3 m cable lengths depending on your installation needs.
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Q6. What standards do these immersion sensors comply with?

A: The AI-200/200-T series helps users comply with leading standards including:

• USFDA (Food & Pharma processes)
• EU GMP (Good Manufacturing Practices)
• ASHRAE Guideline 22 (HVAC & energy efficiency)

Q7. What are the available immersion lengths and thread options?

A: You can select from 50 mm, 75 mm, or 100 mm immersion lengths, with thread options of ½” BSP, ½” NPT, and ¼” BSP to suit your process connections.

Looking to integrate reliable temperature sensing into your process or HVAC system?
Contact IAQ Detectors by Ace Instruments today to discuss your application and get a customized solution with the AI-200/200-T immersion temperature sensors.

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