Shanghai Instrument Temperature Transmitter (Yichuan)

Shanghai Instrument Temperature TransmitterIt consists of circuit units such as reference source, cold end compensation, amplification unit, linearization processing, V/I conversion, disconnection processing, reverse connection protection, and current limiting protection. It amplifies the thermoelectric potential generated by the thermocouple through cold junction compensation, eliminates the nonlinear error between thermoelectric potential and temperature through a linear circuit, and then amplifies and converts it into a 4-20mA current output signal.

principle
Shanghai Instrument Temperature TransmitterIt is an instrument that converts temperature variables into standardized output signals that can be transmitted. Mainly used for measuring and controlling temperature parameters in industrial processes.
A transmitter with sensors usually consists of two parts: the sensor and the signal converter. Sensors are mainly thermocouples or thermistors; Signal converters are mainly composed of measurement units, signal processing and conversion units (due to the standardization of industrial thermal resistance and thermocouple calibration tables, signal converters are also called transmitters when they are independent products). Some transmitters have added display units, and some also have fieldbus functions.
If a transmitter consists of two sensors used to measure temperature differences, there is a given continuous functional relationship between the output signal and the temperature difference. Therefore, it is called a temperature transmitter.
There is a given continuous function relationship (usually a linear function) between the output signal of the transmitter and the temperature variable. Early produced transmitters had a linear function relationship between the output signal and the resistance value (or voltage value) of the temperature sensor.
The standardized output signals are mainly DC electrical signals of 0mA~10mA and 4mA~20mA (or 1V~5V). Other standardized output signals with special regulations cannot be excluded.
Temperature transmitters can be divided into two-wire and four wire systems according to the power supply wiring method.
There are electric unit combination instrument series (DDZ-II, DDZ-III, and DDZ-S) and miniaturized modular, multi-functional intelligent transmitters. The former does not come with sensors, while the latter two types of transmitters can be easily combined with thermocouples or thermistors to form transmitters with sensors.
Technical data
Input signal:
Thermocouples: k, e, j, b, s, t, n. Thermistor: PT100, Cu50, Cu100 three wire system, four wire system. The input signal of the intelligent temperature transmitter can be set arbitrarily through a handheld device and a PC;
Output signal:
Output 4-20mA DC signal within the range of measurement, which is linear with the input signal of thermocouple or thermistor or linear with temperature. The intelligent temperature transmitter outputs a 4-20mA DC signal and superimposes it to comply with the Hart standard protocol for communication; Isolated temperature transmitter: Input and output are isolated, with an isolation voltage of 500V, which increases the ability to resist common mode interference and is more suitable for networking with computers;
Basic error:
0.5%fs、0.2%fs、 Intelligent 0.2% fs;
Wiring method:
Two line system, three line system, four line system;
Display mode:
Four digit LCD displays the on-site temperature, and the intelligent four digit LCD can be used through a PC or handheld device
Set the device to display any of the following parameters: on-site temperature, sensor value, output current, and percentage;
Working voltage:
Ordinary model 12v-35v, intelligent model 12v-45v, rated working voltage is 24V
Allowable load resistance:
500 Ω (24VDC power supply); The maximum load resistance r (max) is 50vmin-12. For example, at a rated operating voltage of 24V, the load resistance can be selected and used within the range of 0-600 Ω.
Work environment:
a: Environmental temperature -25-+80 ℃ (conventional type)
-25-+70 ℃ (digital display type)
-25+75 ℃ (intelligent type)
b: Relative humidity: 5% -95%
c: Mechanical vibration f ≤ 50hz, amplitude ≤ 0.15mm
d: No corrosive gas or similar environment;
9. Environmental impact coefficient: δ ≤ 0.05%/℃.