Temperature transmitter instruction manual

user's Guide

Shanghai Yunou Automation Instrument Co., Ltd.

I. Overview:

SBWR thermocouple temperature transmitter and SBWZ thermal resistance temperature transmitter are field-mounted temperature transmitter units in DDZ-S series instruments. It uses a two-wire transmission method (two wires as a common transmission line for power input and signal output). Transform the thermocouple and thermal resistance signals into an output signal of 4-20mA linear with the input electrical signal or measured temperature. The transmitter can be installed in the junction box of the thermocouple and thermal resistance to form an integrated structure. As a new generation of temperature measuring instrument, it can be widely used in industrial sectors such as metallurgy, petrochemical industry, electric power, light industry, textile, food, national defense and scientific research.

2. Features of temperature transmitter

1. Adopt epoxy resin sealing structure, so it is shockproof and temperature resistant, suitable for installation and use in harsh field environment.

2. It is installed in the junction box of the thermal resistance and thermocouple on site, and directly outputs 4 ~ 20mA, which not only saves the cost of the expensive compensation wire, but also improves the anti-interference ability during the long-distance signal transmission.

3. High precision, low power consumption, wide operating temperature range, stable and reliable operation.

4. The range is adjustable, and has the function of linearization correction, and the thermocouple temperature transmitter has the automatic compensation function of the cold junction.

It has a wide range of applications. It can form an integrated field installation structure with thermocouples and thermal resistances, and can also be installed as a functional module in the testing equipment.

3. Main technical indicators:

1 input: thermal resistance Pt100, Cu50, Cu100

Thermocouple K, E, S, B, T, J, N

2. Output: output 4 ~ 20mA DC signal within the range of measurement range can be linear with the output resistance signal of the thermal resistance thermometer, linear with the input temperature signal of the thermal resistance thermometer; linear with the millivolt signal input by the thermocouple, It can also be linear with the input temperature signal of the thermocouple thermometer.

3. Basic error: ± 0.2%, ± 0.5%

4. Transmission method: two-wire system

5. Transmitter working power supply voltage is minimum 12V, maximum 35V, rated working voltage 24V.

6. Load: The limit load resistance is calculated as follows

RL （max） = 50 × （Vmm-12）

(That is, the load resistance can be selected within the range of 0 ~ 600Ω at 24V) The rated load is 250Ω.

Note: Transmitter with adjustable range, the zero point and full scale need to be adjusted repeatedly when changing the range; the galvanic transmitter must be warmed up for 30 minutes before commissioning.

1. Influence of ambient temperature ≤0.05% 1 ℃

2. Normal working environment:

a. Ambient temperature -25 ℃ ~ + 80 ℃

b. Relative humidity 5% ~ 95%

c. Mechanical vibration f≤55Hz amplitude <0.15mm.

4. Model and category:

5. Wiring method:

Installation wiring diagram of thermal resistance three-wire transmitter

Installation wiring diagram of thermal resistance two-wire transmitter

Thermocouple transmitter installation wiring diagram

Rail type transmitter installation wiring diagram

Wiring diagram of integrated liquid crystal display transmitter

6. Calibration steps of thermocouple temperature transmitter

1. When verifying, connect a potentiometer at the input end, the output signal is electromotive force, connect a 24VDC stabilized power supply at the output end and connect a standard ammeter in series.

2. Zero adjustment: reversely connect the signal input line, make the potentiometer output check the room temperature corresponding electromotive force, adjust the potentiometer Z, so that the ammeter reading is 4mA.

3. Full adjustment: positively connect the signal input line to make the potentiometer output the full range corresponding to the electromotive force, adjust the potentiometer S, so that the ammeter reading is 20mA. (The electromotive force is the value of the full-scale electromotive force minus the corresponding electromotive force at room temperature)

Example: At the inspection site, the temperature transmitter is 7 ° C, the input signal is K, and the temperature transmitter is calibrated from 0 to 1000 ° C. According to the table, the corresponding electromotive force at 7 ° C is 0.277mV, and the corresponding electromotive force at 1000 ° C is 41.269mV. After connecting, the potentiometer outputs 0.277mV, adjust the potentiometer Z to make the ammeter read 4mA; after the positive connection, the potentiometer output reads 40.992mV (41.269mV ~ 0.277mV), adjust the potentiometer S to make the ammeter read 20mA .

7. Calibration steps of thermal resistance temperature transmitter

1. During calibration, connect according to the above typical wiring diagram, connect a standard resistance box (such as ZX-25a) at the input end, connect a 24VDC stabilized power supply at the output end and connect a standard ammeter in series.

2. Change the signal source generator (resistance box) to make it equal to the lower limit of the range, adjust the potentiometer Z so that the ammeter reading is 4 mA, change the signal source to make it equal to the upper limit of the range, adjust the potentiometer S, make the ammeter reading 20 mA.

Example: Input the temperature transmitter with Pt100 range of 0 ~ 100 ℃. After correct wiring, the resistance box outputs 100Ω, adjust the potentiometer Z to make the ammeter read 4 mA; the resistance box output reads 138.50Ω (that is, the corresponding resistance value when the thermal resistance is at 100 ° C), adjust the potentiometer S to make the ammeter The reading is 20 mA.