1、 Overview of outdoor thermometer

Thermocouple temperature transmitter and thermistor temperature transmitter are on-site installed temperature transmission units in the DDZ-S series instruments. It adopts a two-wire transmission method (two wires as power input and a common transmission line for signal output). Transforming thermocouple and thermistor signals into 4-20mA output signals that are linear with the input electrical signal or measured temperature, the transmitter can be installed in the junction box of the thermocouple and thermistor to form an integrated structure. As a new generation of temperature measuring instrument, it can be widely used in industrial sectors such as metallurgy, petrochemicals, power, light industry, textiles, food, and scientific research.

2、 Main features

1. Input: Thermal resistance Pt100, Cu50, Cu100

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

2. Output: Within the range of measurement, outputting a 4-20mA DC signal can be linear with the output resistance signal of the resistance thermometer and linear with the input temperature signal of the resistance thermometer; It can be linear with the millivolt signal input by the thermocouple, or linear with the temperature signal input by the thermocouple thermometer.

3. Basic error: ± 0.2%, ± 0.5%

4. Transmission method: two-wire system

5. The working power supply voltage of the transmitter is 12V low and 35V high, with a rated working voltage of 24V.

6. Load: The maximum load resistance is calculated according to the following formula

RL（max）=50×（Vmm-12）

At 24V, the load resistance can be selected within the range of 0-600 Ω. The rated load is 250 Ω.

Note: The range adjustable transmitter requires repeated debugging of zero and full scale when changing the range;

The thermocouple type transmitter needs to be preheated for 30 minutes before debugging.

7. Environmental temperature impact ≤ 0.05%/1 ℃

8. Normal working environment:

a、 Environmental temperature -25 ℃~+80 ℃

b、 Relative humidity 5%~95%

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