Thermocouple / RTD with Transmitter

Key Features

• Straight union

Technical Specifications

Usually used together with indicating instruments, recording instruments and computer systems, with a 4–20 mA output. It directly measures liquids, steam and gaseous media as well as solid surfaces within 0–1600 °C in various production processes.

Features

○ 2-wire 4–20 mA output with strong anti-interference capability,

○ Saves the cost of extension wires and separately installed transmitters,

○ Wide measuring range,

○ Automatic cold-junction compensation and non-linearity correction circuit,

Operating Principle

The change in thermoelectric EMF (resistance) measured by the thermocouple (RTD) under operating conditions generates an unbalanced signal through the bridge of the temperature transmitter; after amplification it is converted into a 4–20 mA DC signal to the indicating instrument, which then displays the corresponding temperature value.

Main Technical Specifications

○ Applicable standards

IEC584

IEC1515

IEC751

JB/T7391-94

○ RTD (Resistance Thermometer)

○ Thermocouple

○ Output signal: 4–20 mA, load resistance 250 Ω,

Transmission wire resistance 100 Ω

○ Output method: 2-wire

○ Tolerance Class:0.1;0.2;0.5

○ Power supply: 24 V DC ±10%

○ Ingress protection: IP65

The insulation resistance between the instrument output terminals and the case shall be not less than 50 Ω

When a step change in temperature occurs, the time required for the current output signal of the instrument to change to 50% of that step change is usually expressed as t0.5. When the step response stabilisation time of the temperature transmitter does not exceed one fifth of the thermal response stabilisation time t0.5 of the thermocouple (RTD), the thermal response time of the thermocouple (RTD) is taken as the thermal response time of the instrument,

When the step response stabilisation time of the temperature transmitter does not exceed one half of the thermal response stabilisation time t0.5 of the thermocouple (RTD), the thermal response time of the temperature transmitter is taken as the thermal response time of the instrument,

● Instrument wiring method

The basic error of the instrument shall not exceed the combined error of the basic errors of the thermocouple (RTD) and the temperature transmitter.

△=△1+△₂

Δ1 represents the permissible deviation of the thermocouple (RTD),

Δ₂ represents the basic error of the transmitter,

The operating temperature of the temperature transmitter is the sum of the case temperature rise caused by the support tube and the ambient temperature. The case temperature rise caused by the support tube is shown in the figure below:

Note:t₁=260℃ t₂=540℃ t,=850℃

Model Numbering System

Model & Specification

2) Other protection tube materials are supplied per agreement,

Selection Guide

1)Model

2 )Graduation No.

Accuracy class of thermocouple (RTD)

4)Mounting Type

5)Protection Tube Material

6) Length or insertion depth

Example A: Thermocouple with temperature transmitter, Type K, fixed thread M27×2, protection tube 316L, length 450 mm, insertion length 300 mm.

WRNB-230, L=450×300, d IIBT4, protection tube 316L, thread M27×2

130 131 130G 131G

2) Other protection tube materials are supplied per agreement,

3)Nominal pressure≤10MPa。

230 Type 231 230G 231G

2) Other protection tube materials are supplied per agreement,

2) Other protection tube materials are supplied per agreement,

3)Nominal pressure≤2 . 5MPa。

Type 430 / 431 Spray-proof type 430G / 431G

630 waterproof

2) Other protection tube materials are supplied per agreement,

3)Nominal pressure≤30MPa

2) Unless otherwise agreed, L is for reference only; the insertion length of the thermocouple shall equal the U dimension of the thermowell,

3) See for thermowell types。

Waterproof, type 53 / 53A

2) Unless otherwise agreed, L is for reference only; the insertion length of the thermocouple shall equal the U dimension of the thermowell,

3) See for thermowell types

Waterproof, type 73 / 73A

With temperature transmitterExplosion-proof thermocouple / RTD

Applications

Usually used together with indicating instruments, recording instruments and computer systems, with a 4–20 mA output. It directly measures liquids, steam and gaseous media as well as solid surfaces within -200 °C to 1300 °C in various production processes.

Features

○ 2-wire 4–20 mA output with strong anti-interference capability,

○ Saves the cost of extension wires and separately installed transmitters,

○ Wide measuring range,

○ Automatic cold-junction compensation and non-linearity correction circuit,

Operating Principle

The flameproof thermocouple works on the flame-gap principle: when an explosion occurs inside the enclosure, the flame is extinguished and cooled through the joint gap so that the temperature of the exploded flame cannot be transmitted outside the enclosure, thus allowing temperature measurement. The thermoelectric EMF (resistance value) produced by the thermocouple (RTD) generates an unbalanced signal through the bridge of the temperature transmitter; after amplification it is converted into a 4–20 mA DC signal to the indicating instrument, which then displays the corresponding temperature value.

○ Thermocouple

Main Technical Specifications

IEC 584

IEC 1515

IEC 751

GB 3836-2000

JB/T 5518-91

JB/T 7391-94

○ RTD (Resistance Thermometer)

Note: t is the absolute value of the temperature measured by the sensing element.

○ Output signal: 4–20 mA, load resistance 250 Ω, line resistance 100 Ω

Output method: 2-wire

Temperature TransmitterAccuracy Class:0.1;0.2;0.5

Display accuracy: analogue indication class 2.5, digital display class 1.0

Flameproof type: dIIBT4, dIICT5, dIICT6

Intrinsic safety type: iaIICT6

The insulation resistance between the instrument output terminals and the case shall be not less than 50 MΩ.

When a step change in temperature occurs, the time required for the current output signal of the instrument to change to 50% of that step change is usually expressed as T0.5. When the step response stabilisation time of the temperature transmitter does not exceed one fifth of the thermal response stabilisation time τ0.5 of the thermocouple (RTD), the thermal response time of the thermocouple (RTD) is taken as the thermal response time of the instrument; when the step response stabilisation time of the temperature transmitter does not exceed one half of the thermal response stabilisation time t0.5 of the thermocouple (RTD), the thermal response time of the temperature transmitter is taken as the thermal response time of the instrument,

The basic error of a thermocouple (RTD) with temperature transmitter shall not exceed the combined error of the basic errors of the thermocouple (RTD) and the temperature transmitter.

i.e.: Δ = Δ1 + Δ₂

Δ1 is the basic error of the thermocouple or RTD,

Δ₂ is the basic error of the temperature transmitter.

The operating temperature of the temperature transmitter is the sum of the case temperature rise caused by the support tube and the ambient temperature. The case temperature rise caused by the support tube is shown in the figure below:

● Instrument wiring method

○ dIIBT□ class

○ dIICT□ class

Model Numbering System

ThermocoupleClass I、RTD (Resistance Thermometer)Class ASupplied per agreement，2) The protection tube material is 1Cr18Ni9Ti; other materials are supplied per agreement,3)Nominal pressure≤10MPa。

1) ThermocoupleClass I，RTD (Resistance Thermometer)Class ASupplied per agreement，

2) The protection tube material is 1Cr18Ni9Ti; other materials are supplied per agreement,

3)Nominal pressure≤2.5MPa;

Flanges can be supplied as agreed with the user; see page 64 for details

Ordering & Inquiry

For selection guidance, specification confirmation or quotation, please call 0512-57892201, Mobile 13451695112, or submit an online order. Suzhou Dingluxuan Sensor Technology Co., Ltd. provides a complete matching service from temperature sensing elements to complementary ceramic insulation parts.

To order this product or get selection guidance, please call +86 512-57892201 or submit an online order.