Cryogenic Temperature Measurement for LNG Tanks
The Rosemount 614 is specifically designed for temperature measurement in cryogenic and refrigerated tanks. Unlike the Rosemount 566, which uses multiple immersed Pt-100 elements to create a tank temperature profile, the Rosemount 614 is designed for spot temperature measurement at specific locations.
This makes it particularly useful during LNG tank commissioning and cool-down, as well as for monitoring temperatures in the tank insulation space where abnormal temperature changes can indicate a potential leak.
Designed for Cool-Down Monitoring and Leak Detection
During the first filling and cool-down of an LNG full-containment tank, temperature changes need to be monitored at multiple locations.
The Rosemount 614 uses a mineral-insulated flexible steel cable, allowing individual temperature sensors to be positioned where temperature monitoring is required. The sensor can also be installed in the tank's insulation space for distributed leak detection.
Multiple Rosemount 614 sensors can be connected to a Rosemount 2240S Multi-input Temperature Transmitter through a conical connection or junction box, allowing a larger number of temperature monitoring points to be integrated into the tank gauging system.
Pt-100 Sensing for Cryogenic Applications
The Rosemount 614 uses Pt-100 spot elements according to IEC 60751:2022.
It is available with single or dual sensing elements and can be configured with Class A, Class B, or calibrated sensor accuracy depending on the selected configuration.
The specified sensor element accuracy includes:
- Class A: ±(0.15 + 0.002 × |t|) °C
- Class B: ±(0.30 + 0.005 × |t|) °C
- Calibrated: ±0.02 °C (±0.036 °F)
The calibrated specification provides high accuracy for applications where precise cryogenic temperature monitoring is required.
Robust Mineral-Insulated Construction
The sensor uses a 4.5 mm diameter AISI 316L protective sheath filled with compressed magnesium oxide powder.
This mineral-insulated construction provides mechanical protection while allowing the sensor to operate across a wide cryogenic temperature range. The immersed components use stainless steel construction suitable for demanding tank environments.
Key Technical Highlights
- Sensor type: Cryogenic spot temperature sensor
- Temperature element: Pt-100
- Element standard: IEC 60751:2022
- Number of elements: Single or dual
- Temperature range: -200 to +100 °C
- Pressure range: ≤50 bar
- Class A accuracy: ±(0.15 + 0.002 × |t|) °C
- Class B accuracy: ±(0.30 + 0.005 × |t|) °C
- Calibrated accuracy: ±0.02 °C
- Protective sheath: AISI 316L
- Sheath diameter: 4.5 mm
- Sensor tip diameter: 6 mm
- Maximum overall length: 300 m
- Connection options: Fixed or sliding 1/8 in. NPT or 1/2 in. NPT, depending on configuration
- Cable: Mineral-insulated flexible steel cable
- Compatible transmitter: Rosemount 2240S Multi-input Temperature Transmitter
- Applications: Cryogenic tanks, refrigerated tanks, LNG tank cool-down and leak detection
Typical Applications
LNG Tank Cool-Down Monitoring
The Rosemount 614 can be installed at multiple locations within a full-containment LNG tank to monitor temperature distribution during the cool-down procedure.
Cryogenic Tank Leak Detection
Temperature sensors can be positioned in the insulation space between tank structures. Abnormal temperature changes can help identify potential leakage conditions.
Refrigerated Storage Tanks
The sensor is suitable for temperature monitoring in refrigerated and cryogenic storage applications where conventional temperature sensors may not be appropriate.
LNG Storage and Tank Gauging
Rosemount 614 sensors can be integrated with the Rosemount 2240S and broader Rosemount tank gauging systems for distributed temperature monitoring.
Frequently Asked Questions
What is the Rosemount 614 used for?
The Rosemount 614 is a cryogenic spot temperature sensor designed for temperature measurement in LNG and refrigerated storage tanks. Its main applications include cool-down monitoring and leak detection.
What is the temperature range of Rosemount 614?
The Rosemount 614 has a specified liquid temperature range of -200 to +100 °C (-328 to +212 °F).
What type of temperature element does Rosemount 614 use?
The Rosemount 614 uses Pt-100 spot elements according to IEC 60751:2022. Single or dual elements are available depending on configuration.
What is the accuracy of Rosemount 614?
The available sensor accuracy depends on the selected element and calibration:
Class A: ±(0.15 + 0.002 × |t|) °C
Class B: ±(0.30 + 0.005 × |t|) °C
Calibrated: ±0.02 °C
The ±0.02 °C specification applies to calibrated sensors.
Is Rosemount 614 suitable for LNG?
Yes. The Rosemount 614 is specifically designed for cryogenic and refrigerated tanks, including LNG storage applications. Emerson identifies it for cool-down monitoring and leak detection in full-containment LNG tanks.
What is the difference between Rosemount 614 and Rosemount 566?
The Rosemount 614 is a spot temperature sensor mainly used for cool-down monitoring and leak detection.
The Rosemount 566 is a multiple spot temperature sensor with up to 16 Pt-100 elements positioned at different heights to measure tank temperature profile and average product temperature.
In simple terms:
Rosemount 614 → spot temperature / cool-down / leak detection
Rosemount 566 → multiple-point temperature profile / average temperature / stratification monitoring
Can multiple Rosemount 614 sensors be used together?
Yes. Multiple Rosemount 614 sensors can be connected to a Rosemount 2240S Multi-input Temperature Transmitter through a conical connection or junction box.
What transmitter is used with Rosemount 614?
The Rosemount 614 is designed to integrate with the Rosemount 2240S Multi-input Temperature Transmitter. The 2240S is used to collect temperature measurements from the sensors and integrate them into the tank gauging system.
How long can the Rosemount 614 sensor be?
The maximum specified overall sensor length is 300 m (984 ft), depending on configuration.
What material is the Rosemount 614 sheath made from?
The protective sheath is AISI 316L stainless steel with compressed magnesium oxide insulation. The sensor tip is also made from AISI 316L stainless steel.
