The **M2UDS-DE-R** is a specific model within the **M2UDS Series** of digital capacitive level switches manufactured by **Nohken**. These devices are primarily used for point level detection of powders, granules, and liquids. Below is a detailed breakdown of its electronic components, specifications, and technical features. --- ## 1. Technical Specifications The "DE" suffix typically denotes a specific configuration regarding output and power supply. | Feature | Specification | | :--- | :--- | | **Detection Method** | Capacitive (Admittance) | | **Power Supply** | 20 to 250V AC/DC (Universal) | | **Output Type** | Relay Contact (SPDT) | | **Contact Capacity** | 250V AC 5A / 30V DC 5A (Resistive load) | | **Power Consumption** | Approx. 2W / 5VA | | **Operating Temp** | -20°C to +60°C (Electronic insert) | | **Sensitivity Range** | 0.5pF to 20pF (Adjustable) | --- ## 2. Core Electronic Components The internal circuitry is divided into three functional blocks: ### A. Sensing Circuit (The Probe) The probe acts as one plate of a capacitor. When the medium (material) touches the probe, the capacitance changes relative to the ground (tank wall). * **Guard Circuit:** Often includes a "Shield" or "Guard" section to prevent false triggering caused by material buildup or coating on the probe. ### B. Signal Processing Unit * **Oscillator:** Generates a high-frequency signal to detect impedance changes. * **Comparator/Microprocessor:** Compares the measured capacitance against a pre-set threshold (Sensitivity). * **Delay Timer:** Integrated electronics usually include a "Time Delay" (typically 0–10 seconds) to prevent "chattering" caused by turbulent liquids or falling material. ### C. Output Module * **Relay (R):** The "R" in the model name stands for **Relay**. It provides a dry contact output. * **Fail-Safe Switch:** A physical slide switch on the PCB that allows the user to select **HLFS** (High Level Fail-Safe) or **LLFS** (Low Level Fail-Safe). --- ## 3. Wiring and Terminals The electronic base features a terminal block for field wiring. | Terminal No. | Function | Description | | :--- | :--- | :--- | | 1 & 2 | Power Input | 20-250V AC/DC (Non-polarized) | | 3 | COM | Common Relay Contact | | 4 | NC | Normally Closed Contact | | 5 | NO | Normally Open Contact | | E | Ground | Connection to tank/Earth | --- ## 4. Operational Indicators The M2UDS electronics include LED indicators for real-time diagnostics: 1. **Green LED (Power):** Indicates the unit is energized. 2. **Red LED (Status):** Indicates the relay is energized (Material detected or Fail-safe state). 3. **Sensitivity Potentiometer:** A multi-turn trimmer used to calibrate the device based on the dielectric constant of the material being measured. ---