FOXBORO E69F-TI2-S dual line temperature transmitter



FOXBORO E69F-TI2-S dual line temperature transmitter

Product Overview

The FOXBORO E69F-TI2-S dual line temperature transmitter is a high-precision signal conversion device developed by FOXBORO specifically for industrial temperature monitoring scenarios. As a key front-end component in process automation control systems, its core function is to accurately convert simulated signals or resistance signals collected by on-site temperature sensors into 4-20mA dual line current signals that meet industrial standards, achieving long-distance and low interference transmission of temperature parameters.

This product adopts a dual line design, which combines signal transmission and power supply functions without the need for additional power cables, effectively simplifying on-site wiring and reducing construction costs. With its compact structural design, wide range adaptability, and excellent anti-interference performance, it is widely used in industries such as petrochemicals, power generation, metallurgy and steel, food processing, and pharmaceuticals. It can adapt to various common temperature sensors such as thermocouples (such as K, J, T types) and thermistors (such as PT100, Cu50), providing reliable data support for temperature monitoring, closed-loop control, and safety interlocking in industrial production processes.

Specification parameters

The specification parameters of FOXBORO E69F-TI2-S dual line temperature transmitter are set based on industrial grade accuracy and stability requirements, and the core technical indicators are shown in the following table:

parameter category

specific indicators

Input characteristics

Suitable sensor types: thermocouple (K, J, T, E, R, S type), thermistor (PT100, PT1000, Cu50, Cu100); Input signal range: Thermocouple -270 ° C to 1760 ° C (depending on model), Thermistor -200 ° C to 850 ° C

output characteristics

Output signal: 4-20mA DC dual line current signal; Output accuracy: ± 0.1% FS; load capacity: 0-500 Ω (when the supply voltage is ≥ 12V), 0-1000 Ω (when the supply voltage is ≥ 24V)

power supply parameters

Power supply mode: dual line system (shared signal and power supply); Supply voltage: 12-36V DC; Typical power consumption: ≤ 1.2W (when powered by 24V DC)

environmental parameters

Working temperature: -40 ° C to+85 ° C; Storage temperature: -50 ° C to+100 ° C; Relative humidity: 5% to 95% (no condensation); Protection level: IP67 (on-site installation type), IP20 (disk mounted type)

Accuracy and stability

Basic error: ± 0.05% FS; Long term stability: ≤± 0.1% FS/year; Cold end compensation error: ± 0.2 ° C (when the ambient temperature is 0-60 ° C)

Anti-interference performance

Common mode rejection ratio (CMRR): ≥ 120dB@50 /60Hz; Differential Mode Rejection Ratio (DMRR): ≥ 80dB@50 /60Hz; compliant with IEC 61000-4-2/3/4/6 anti-interference standards

Physics and Installation

Shell material: die cast aluminum alloy (on-site type), ABS engineering plastic (disc mounted type); Installation methods: threaded installation (M20 × 1.5), DIN rail installation, panel installation; Weight: Approximately 200g

Certification and Compliance

Explosion proof rating: Ex d IIB T6 Ga (optional); Safety certifications: ATEX, IECEx, UL, CSA; Electromagnetic compatibility certification: CE, FCC

Performance characteristics

1. High precision signal conversion and temperature compensation

Equipped with a 24 bit high-precision ADC conversion chip and dedicated temperature compensation algorithm, it can digitize sensor signals with a basic error controlled within ± 0.05% FS, far exceeding the industry average level. For thermocouple sensors, multi-stage cold end compensation technology is adopted, which collects real-time environmental temperature through a built-in high-precision environmental temperature sensor. The compensation error is as low as ± 0.2 ° C, effectively eliminating the influence of environmental temperature changes on measurement accuracy and ensuring measurement stability over a wide temperature range.

2. Dual line design and low power consumption characteristics

Adopting a standard dual wire architecture, the 4-20mA output signal shares the same pair of wires with the power supply, without the need for additional power lines, greatly simplifying on-site wiring work and reducing engineering costs and maintenance difficulties. The optimized circuit design ensures that the device's power consumption is controlled within 1.2W, and it can still operate stably under low power supply voltage of 12V DC, adapting to different power supply scenarios while reducing line losses. It supports signal transmission distances of up to 1000 meters (when using 0.5mm ² wires).

3. Super strong anti-interference and environmental adaptability

The circuit adopts a triple isolation design (input-output power supply), with a common mode rejection ratio of up to 120dB, which can effectively resist strong electromagnetic interference, power grid fluctuations, and grounding loop interference in industrial sites, ensuring the stability of signal transmission. The enclosure protection level reaches IP67, which can be directly installed in damp and dusty on-site environments, and can withstand low temperatures of -40 ° C and high temperatures of 85 ° C. It can operate stably in harsh industrial scenarios without additional protective measures.

4. Flexible adaptation and convenient debugging

Supports multiple types of thermocouples and thermal resistance sensors, and can configure sensor types, measurement ranges, output methods, and other parameters through dedicated configuration software or handheld programmers without the need to replace hardware modules, adapting to different temperature monitoring needs. Some models are equipped with LCD display screens, which can display measured temperature and equipment status in real time, and support button local debugging, simplifying on-site calibration and troubleshooting processes.

5. Safe and reliable industrial grade design

The optional explosion-proof version meets the Ex d IIB T6 Ga explosion-proof rating and can be used in Zone 1 and Zone 2 hazardous environments, suitable for flammable and explosive scenarios such as petroleum and chemical industries. The device is equipped with overcurrent, overvoltage, and short-circuit protection circuits, which automatically limit the current when the output circuit is abnormal, avoiding equipment damage and line faults. The shell is made of high-strength materials, with good impact and corrosion resistance, meeting the reliability requirements for long-term operation in industrial sites.

Working principle

The FOXBORO E69F-TI2-S dual line temperature transmitter operates with the core workflow of "signal acquisition signal processing conversion output power supply coordination", utilizing the dual line system characteristics to achieve efficient transmission of signals and power supply. The specific working principle is as follows:

1. Sensor signal acquisition

Temperature sensors (thermocouples or thermistors) generate corresponding electrical signals based on temperature changes at measurement points: thermocouples generate millivolt level thermoelectric potentials corresponding to temperature differences based on the Seebeck effect; Thermistors generate resistance changes corresponding to temperature based on the temperature effect of resistance. The transmitter receives these raw signals through a dedicated input terminal, and the input circuit is equipped with precision resistors and filtering circuits to preliminarily filter out high-frequency interference signals.

2. Signal processing and compensation

The collected raw signal is transmitted to a 24 bit high-precision ADC conversion module, which converts the analog signal into a digital signal and sends it to the microprocessor. The microprocessor executes a preset signal processing algorithm: combining the thermocouple signal with the cold junction temperature collected by the built-in environmental temperature sensor, the cold junction compensation algorithm is used to eliminate the influence of cold junction temperature fluctuations; For thermal resistance signals, a three wire or four wire measurement method (supported by some models) is used to eliminate errors caused by wire resistance and ensure the accuracy of resistance measurement.

3. 4-20mA signal conversion and output

The processed digital temperature signal is converted into a corresponding 4-20mA current signal instruction by the microprocessor according to the preset range ratio, driving the output stage circuit (operational amplifier and power transistor) to generate stable current output. The lower limit of 4mA of the output signal corresponds to the lower limit of the measurement range, and the upper limit of 20mA corresponds to the upper limit of the measurement range, achieving a linear correspondence between temperature and current signals, which is convenient for the upper control system to directly receive and interpret.

4. Dual line power supply and collaborative work

The transmitter adopts a dual line power supply mode, and the upper system or DC power supply provides 12-36V DC working power to the transmitter through the output 4-20mA signal wire. During the transmission process, the current signal not only carries temperature measurement information, but also provides energy for the internal circuit of the transmitter, achieving "one line dual-use". In circuit design, an efficient power management module is used to convert the input voltage into a stable voltage required by the internal circuit, ensuring the coordinated stability of signal conversion and power supply.

Precautions

1. Installation and environmental specifications

-The installation location should avoid direct contact with high-temperature heat sources, strong corrosive media, and strong electromagnetic radiation sources (such as high-power frequency converters and welding machines), and the distance from these devices should not be less than 1 meter; In explosion-proof situations, it is necessary to select the corresponding explosion-proof grade model and strictly follow the explosion-proof installation specifications for wiring and sealing.

-On site installation of transmitters requires ensuring good sealing of the threaded interface, using waterproof gaskets, and tightening torque controlled at 15-20N · m to prevent rainwater and dust from entering the internal circuit; The disk mounted transmitter should be installed in a well ventilated control cabinet to avoid close contact with heating elements.

-The connecting wire between the sensor and the transmitter should use shielded cables, with the shielding layer grounded at one end (grounding resistance ≤ 4 Ω). The length of the wire should not exceed 50 meters to avoid signal attenuation and interference.

2. Wiring operation and power requirements

-Before wiring, the power supply of the upper system and the transmitter must be cut off, and live wiring is strictly prohibited; Thermocouple wiring needs to distinguish between positive and negative poles. Connecting them in reverse will result in measurement errors or equipment damage; The wiring of thermal resistors should ensure consistent wire resistance and avoid using wires of different specifications.

-The power supply should be stable within the range of 12-36V DC, with fluctuations not exceeding ± 10%. It is recommended to connect a 1A fuse in series in the power circuit to prevent overcurrent damage to the equipment; The cross-sectional area of the double wire system should not be less than 0.5mm ² to ensure the stability of power supply current and signal transmission.

-When multiple transmitters are used in parallel, it is necessary to ensure that the total load current does not exceed the rated output current of the power supply to avoid overloading the power supply and causing abnormal operation of all equipment.

3. Debugging and Calibration Taboos

-Parameter debugging requires the use of FOXBORO specialized configuration software or certified handheld programmers. Non specialized tools are prohibited from modifying internal parameters to avoid measurement errors caused by parameter confusion; After debugging, it is necessary to lock the parameters to prevent accidental modifications.

-The recommended regular calibration cycle is 1 year, and calibration needs to be carried out on a standard temperature calibration device. Select the corresponding calibration point according to the sensor type to ensure that the calibration environment temperature is stable at 20 ± 5 ° C, and avoid environmental temperature affecting calibration accuracy.

-Do not use in scenarios where the temperature at the measurement point exceeds the range of the sensor and transmitter. Exceeding the range measurement will cause equipment damage and may produce incorrect output signals, affecting the control logic of the upper system.

4. Maintenance and troubleshooting

-During daily maintenance, it is necessary to regularly check whether the wiring terminals are loose, whether the casing is damaged, and whether the sealing is good. Especially in scenarios with high vibration, a terminal tightening inspection should be conducted once a month; When cleaning equipment, use a dry soft cloth and do not wipe with water or corrosive cleaning agents.

-If there is an abnormal output signal, first check whether the sensor is normal (replace the standard sensor for testing), then check whether the wiring is secure and whether the wires are damaged, and finally check the internal parameters and fault codes of the device through configuration software to gradually troubleshoot the problem.

-When the equipment malfunctions, it needs to be repaired by qualified technicians. It is prohibited to dismantle the casing without authorization (dismantling explosion-proof equipment will damage the explosion-proof structure). Maintenance requires the use of FOXBORO original spare parts to ensure equipment performance and safety compliance.