Does the thermometer need to be heated to change?

Whether to use a temperature transmitter depends on a comprehensive consideration of the following factors: 1. **Signal transmission distance:** If the distance from where the PT100 signal is generated to the DCS or PLC is long, signal interference or voltage drops may occur; in such cases, a temperature transmitter should be used to address issues related to interference and accuracy. 2. **Isolation and protection function:** Temperature variation provides an isolation effect, which helps to protect the sensor side from interference and overvoltage in the field, thus offering a certain level of protection. If the on-site environment is complex (intense electromagnetic interference, high voltage, etc.), it is recommended to use a heating transformer. 3. **Convenience of repair and maintenance:** The inclusion of temperature control does add additional components to the equipment, which also increases the likelihood of failures. When a temperature-related failure occurs, it is necessary to carry out separate repairs or replacements, thereby increasing maintenance costs and complexity over time. 4. **Equipment quality factors:** If the temperature controllers previously used often exhibited drift or malfunctions, it is recommended to opt for products from reputable brands and of high quality, so as to enhance reliability and minimize the frequency of maintenance. Recommended solution: – If the measurement distance is large, there is significant environmental interference, and high precision is required for the instrument signals, it is advisable to use a temperature-sensitive element with stable performance ； - If the measurement point is close to the control system and there is little interference in the field, it is possible to omit temperature compensation and use high-quality three-wire or four-wire PT100 sensors directly connected to the card (high-precision AI card). In short, after weighing the pros and cons, the key is to choose the appropriate method based on the specific conditions on site. .

Calling it a temperature sensor simplifies data transmission, and the quality of such sensors produced by reputable manufacturers is guaranteed

In addition to the answer for the first floor, adding a temperature transmitter can also standardize the type of AI cards

It is recommended to add temperature sensors, or directly install rail-mounted temperature sensors within the junction box. In cases where the installation environment is complex and the cables are long, it becomes difficult to identify interference issues later on. It is also better to use fewer components in the control cabinet, as this will make future modifications and upgrades easier!

A temperature sensor that does not require display can cost around ten yuan or so. It is generally not recommended to use a PT100 sensor with three wires connected to a DCS cabinet; what is transmitted in this case is a resistance signal, which is actually a voltage signal and thus prone to interference. Additionally, three wires are needed, and a transmitter is required to convert the signal into a current signal. Current signals are more resistant to interference, and ordinary current sensors are cheaper than PT100 sensors. The ordinary current sensors produced by Zhejiang University have six measurement points, while the resistance sensors have only four. If the thermometer is placed in a harsh environment, PT100 can be used; it has a simple structure, no electrical components, and is durable

The anti-interference capability of 4~20mA standard signals is stronger than that of resistance signals, and their stability is better； It is possible to reduce the types of DCS cards; if there are future modifications, having a unified signal type will be more convenient ； Big-brand products have high temperature-change reliability, with a very low chance of problems occurring ；