Description

How Does an FLP Digital Temperature Scanner Work?
Key Components
1. Flameproof Enclosure: Constructed from materials like aluminum LM-6 or stainless
steel, certified for hazardous areas with ingress protection ratings like IP65 or IP66.
2. Sensor Inputs: Supports multiple inputs from RTD Pt-100, thermocouples (e.g., J, K, T,
R, S), or analog signals (4-20 mA) for versatile temperature measurement.
3. Digital Display: High-visibility LED or LCD (e.g., 4-digit, 7-segment) shows
temperature readings for each channel, often with auto or manual scanning modes.
4. Microcontroller: Processes multiple sensor signals, supports software calibration, and
enables programmable features like scan time, alarm setpoints, or channel skipping.
5. Communication Interfaces: Optional RS485 Modbus, RS232, or 4-20 mA
retransmission for integration with SCADA, PLC, or DCS systems.
6. Power Supply: Typically operates on 230 V AC, 110 V AC, or 24 V DC, designed for
low power consumption.
7. Alarm Outputs: Relay outputs for high/low temperature alarms, enhancing process
safety and control.
Working Principle
 Sensor Connection: Multiple temperature sensors are connected to the scanner, each
monitoring a specific point in the process (e.g., reactor, pipeline, or furnace).
 Signal Processing: The microcontroller converts sensor signals into temperature values,
compensating for factors like lead wire resistance in RTDs or cold junction compensation
for thermocouples.
 Display and Scanning: The scanner displays temperatures either for a selected channel
or in auto-scan mode, cycling through channels at programmable intervals (e.g., 1–60
seconds).
 Safety: The flameproof enclosure ensures safe operation in hazardous areas (Zone 1 or
Zone 2), preventing ignition of flammable gases or vapors.

 Data Integration: Optional communication interfaces or retransmission outputs enable
data logging, remote monitoring, or integration with control systems.
 Alarms: Programmable high/low setpoints trigger alarms or control actions (e.g., relay
outputs) to maintain process safety.