1. Introduction
The FNIRSI LCR-ST2 is a state-of-the-art tweezer-type LCR meter designed for precise measurement of electronic components. This multifunctional and portable testing instrument supports accurate measurement of resistance, capacitance, inductance, and diodes, along with voltage measurement up to 30V. Its advanced measurement technology ensures high accuracy and stability, making it an indispensable tool for electronics enthusiasts, engineers, and technicians.
Featuring a 1.47-inch high-definition color display and a magnetic attachment design, the LCR-ST2 offers enhanced ease of use and portability. It is powered by a built-in 300mAh lithium battery, providing approximately 3 hours of continuous operation. The device supports five selectable test frequencies: 100 Hz, 120 Hz, 1 kHz, 10 kHz, and 100 kHz.
The unique tweezer-style design is ideal for fine operations in confined spaces, enabling quick testing of Surface Mount Devices (SMD) and other electronic components. Additionally, the LCR-ST2 includes a sweep function for rapid scanning of component parameters across its full frequency range (100 Hz–100 kHz), providing multi-frequency data with a single press for accurate component characterization. Its intelligent sorting function automatically classifies and filters components, significantly improving batch testing efficiency. The dual-mode simultaneous display feature allows two measurement modes to be shown concurrently, making result analysis more intuitive.
2. Key Features
- High Accuracy Measurement: Precise LCR, ESR, Diode, and Voltage measurements.
- Multi-Frequency Testing: Supports 100Hz, 120Hz, 1kHz, 10kHz, and 100kHz test frequencies.
- Dual-Mode Design: Easily switch between tweezer-style probes for SMD components and Kelvin clips for plug-in components.
- Smart Auto-Rotate Screen: Display automatically adapts for left- or right-handed use.
- Intelligent Sorting & Comparison: Identify abnormal components with preset values and tolerances.
- Sweep Mode: Rapidly scan component parameters across the full frequency range (100Hz-100kHz).
- Four RMS Test Levels: Multi-range voltage levels (0.1V, 0.3V/0.6V, 1.0V) for precise and versatile measurements.
- Dual-Parameter Display: Simultaneous display of two measurement modes for intuitive analysis.
- Built-in Battery: 300mAh lithium battery with approximately 3 hours of battery life.
- Type-C Charging: Convenient USB Type-C charging port.
- Auto Shutdown: Configurable auto power-off settings (Never, 5min, 15min, 30min).
- Calibration Function: Supports Open, Short, and Multiple Resistor calibration.
- Magnetic Attachment: High-strength magnetic design for anti-loss and space-saving.
- Gold-Plated Tweezer Head: Ensures high resistance and stability.
3. Package Contents
The FNIRSI LCR-ST2 is available in two sets. Please verify the contents of your package upon receipt.
3.1. LCR-ST2 Set 1
Image: LCR-ST2 Set 1 contents, including the LCR-ST2 Tweezer, storage bag, curved tip, shorting plate, and data cable.
- LCR-ST2 Host + Tweezer-Style Clip
- Storage Bag
- Curved Tip
- Shorting Plate
- Data Cable
3.2. LCR-ST2 Set 2
Image: LCR-ST2 Set 2 contents, including the LCR-ST2 Tweezer, storage bag, curved tip, shorting plate, Kelvin test clip, and data cable.
- LCR-ST2 Host + Tweezer-Style Clip
- Storage Bag
- Curved Tip
- Shorting Plate
- Kelvin Test Clip
- Data Cable
4. Setup and Preparation
4.1. Charging the Device
Before initial use, fully charge the LCR-ST2. Connect the provided Data Cable to the Type-C charging port on the device and to a standard USB power adapter (not included). The battery indicator on the display will show charging status.
Image: Close-up of the Type-C charging port on the LCR-ST2.
4.2. Attaching Test Probes
The LCR-ST2 supports two types of test probes: the integrated tweezer-style clip and external Kelvin test clips (included in Set 2). You can effortlessly switch between these modes.
Image: Illustration of how to switch between the integrated tweezer-style clip and external Kelvin clips by pulling out or plugging in the USB-C connector.
- Tweezer-Style Clip: This is the default configuration. Ensure the tweezer tips are securely attached. For different component types or reach, you can replace the straight tips with the curved tips (included).
- Kelvin Test Clip (Set 2 only): To use the Kelvin test clips, gently pull out the tweezer-style clip from the main unit. Then, plug in the Kelvin test clip connector into the Type-C port of the LCR-ST2.
Image: Demonstrates the use of Kelvin clips for plug-in components and straight/curved tips for SMD components.
4.3. Power On/Off
Press and hold the power button (usually located on the top of the device) to turn the LCR-ST2 on or off.
5. Operating Instructions
5.1. Basic Measurement (Auto Recognition)
The LCR-ST2 features automatic recognition for Resistance (R), Capacitance (C), and Inductance (L). Simply power on the device and touch the component with the probes. The device will automatically detect the component type and display the measurement results on the 1.47-inch HD color screen.
Image: Examples of capacitance, resistance, inductance, diode, and voltage measurements using both tweezer and Kelvin clip modes.
5.2. Selecting Test Frequency
The LCR-ST2 supports five test frequencies: 100Hz, 120Hz, 1kHz, 10kHz, and 100kHz. You can cycle through these frequencies using the dedicated frequency selection button (refer to the device's interface for button location, typically marked with 'M' or a frequency symbol).
Image: Diagram illustrating the five test frequencies (100Hz, 120Hz, 1kHz, 10kHz, 100kHz) and their recommended applications for different component types.
- 100kHz: High-frequency components, RF inductors, RF capacitors, resonant circuits.
- 10kHz: Small-capacitance ceramic capacitors, high-frequency inductors, RF components.
- 1kHz: Industry standard test frequency, general-purpose film capacitors, ceramic capacitors, power inductors, etc.
- 100/120Hz: Large-capacitance electrolytic capacitors, power-frequency components, motor windings.
5.3. RMS Test Levels
The device offers multiple RMS test voltage levels for precise measurements:
Image: Diagram explaining the three RMS test levels: 0.1V for safe testing, 0.3V/0.6V for general use, and 1.0V for high-level excitation.
- 0.1V Safe Testing: Applicable to low-impedance, easily saturated devices.
- 0.3V / 0.6V General Use: Meets the efficient testing needs of most common devices.
- 1.0V High-Level Excitation: Enables more accurate & stable measurements.
5.4. Intelligent Sorting & Comparison
This feature allows you to set tolerance values to quickly identify components that are within or outside specified parameters. This is particularly useful for batch testing and quality control.
Image: Example of Intelligent Sorting & Comparison, showing a 'PASS' result for a component within tolerance and an 'NG' (No Good) result for an abnormal component.
5.5. Sweep Mode
The sweep function allows you to rapidly scan component parameters across the full frequency range (100Hz–100kHz) and obtain multi-frequency data with a single press. This helps in understanding component behavior at different frequencies.
5.6. Voltage Measurement
The LCR-ST2 can measure voltages up to ±30V. When in voltage measurement mode, connect the probes to the points where you want to measure the voltage.
Image: LCR-ST2 connected via Kelvin clips to measure voltage on a circuit board.
5.7. Series-Parallel Equivalent Model
The device can display measurements in both series and parallel equivalent models, eliminating parasitic interference and delivering true R/L/C data. This is useful for analyzing components with different Q values.
Image: Explanations and circuit diagrams for Series Model (low Q value) and Parallel Model (high Q value) for LCR measurements.
- Series Model (Low Q Value < 10): Suitable for low impedance/high frequency, large capacitance/small resistance/ESR testing.
- Parallel Model (High Q Value > 10): Suitable for high impedance/low frequency, small capacitance/large resistance/insulation testing.
5.8. Auto-Rotate Screen
The screen automatically rotates to adapt to left- or right-handed use, ensuring comfortable and effortless operation.
Image: Demonstrates the smart auto-rotate screen feature for adapting to user's hand orientation.
5.9. Menu Navigation and Settings
The LCR-ST2 has a user-friendly interface. Use the navigation buttons (refer to the device's interface) to access settings such as auto power-off time, language (English/Chinese), screen brightness, and sound.
Image: Overview of core advantages, including various features and settings available on the device.
6. Specifications
| Parameter | Value |
|---|---|
| Model | LCR-ST2 |
| Display | 1.47-inch HD color screen |
| Battery | 300mAh lithium battery |
| Battery Life | Approx. 3 hours |
| Charging Port | Type-C |
| Dimensions | 31 x 170.7 x 20.3 mm |
| Net Weight | Approx. 60.8g |
| Operating Temperature | 0℃–50℃ (≤75%RH) |
| Storage Temperature | –20℃–60℃ (≤75%RH) |
| Auto Power-off | Never / 5min / 15min / 30min |
| Language | English / Chinese |
| Calibration | Open / Short / Multiple resistor calibration |
| Adjustable Settings | Screen brightness & sound |
| Auto Recognition | R/C/L |
| Capacitance Range | 1pF–22mF |
| Inductance Range | 1µH–10H |
| Resistance Range | 10mΩ–10MΩ |
| Diode Forward Voltage Detection | ≤0.7V |
| Voltage Range | ±30V |
| Frequency Sweep | 100Hz–100kHz |
| Certification | CE, FCC, RoHS, UL |
| DIY Supplies | Electrical |
| Accuracy Class | 1% |
| Power Supply | DC |
| Display Type | Digital Only |
Detailed Capacitance Accuracy:
| Range | 100Hz/120Hz | 1KHz | 10KHz | 100KHz |
|---|---|---|---|---|
| 1mF-22mF | 5%±3 | 5%±3 | / | / |
| 1µF-1mF | 2%±3 | 2%±3 | 5%±3 | 5%±3 |
| 1nF-1µF | 2%±3 | 0.5%±3 | 0.5%±3 | 5%±3 |
| 1pF-1nF | / | 2%±3 | 2%±3 | / |
Detailed Inductance Accuracy:
| Range | 100Hz/120Hz | 1KHz | 10KHz | 100KHz |
|---|---|---|---|---|
| 1H-10H | 5%±3 | 5%±3 | / | / |
| 1mH-1H | 2%±3 | 2%±3 | / | / |
| 10µH-1mH | 2%±3 | 0.5%±3 | 0.5%±3 | 5%±3 |
| 1µH-10µH | / | 2%±3 | 2%±3 | 5%±3 |
Detailed Resistance Accuracy:
| Range | 100Hz/120Hz | 1KHz | 10KHz | 100KHz |
|---|---|---|---|---|
| 1MΩ-10MΩ | 5%±3 | 5%±3 | / | / |
| 1kΩ-1MΩ | 1%±3 | 0.5%±3 | 1%±3 | / |
| 1Ω-1kΩ | 1%±3 | 0.5%±3 | 1%±3 | 5%±3 |
| 10mΩ-1Ω | 2%±3 | 2%±3 | 2%±3 | / |
Diode & Voltage Accuracy:
| Range | 100Hz/120Hz | 1KHz | 10KHz | 100KHz |
|---|---|---|---|---|
| On-state voltage <=0.7V | / | / | / | / |
| ±30V | / | / | / | / |
Image: Comprehensive table of product parameters, including detailed accuracy for capacitance, inductance, resistance, diode, and voltage measurements across different frequencies.
7. Maintenance and Care
- Cleaning: Use a soft, dry cloth to clean the device. Do not use abrasive cleaners or solvents.
- Storage: Store the LCR-ST2 in its storage bag in a cool, dry place, away from direct sunlight and extreme temperatures.
- Battery Care: To prolong battery life, avoid fully discharging the battery frequently. Charge the device regularly, especially if it will be stored for an extended period.
- Probe Care: Keep the probe tips clean and free from debris. Replace worn or damaged tips to ensure accurate measurements.
- Calibration: Perform calibration (Open / Short / Multiple resistor calibration) periodically or if you suspect measurement inaccuracies. Refer to the device's menu for calibration options.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on | Low battery or device malfunction. | Charge the device for at least 30 minutes. If it still doesn't turn on, contact support. |
| Inaccurate readings | Dirty probes, uncalibrated device, or incorrect test frequency. | Clean probe tips. Perform a calibration. Ensure the correct test frequency is selected for the component. |
| Screen not rotating automatically | Auto-rotate feature might be disabled or a software glitch. | Check settings to ensure auto-rotate is enabled. Restart the device. |
| Cannot switch between tweezer and Kelvin clip | Connector not fully inserted or removed. | Ensure the connector is firmly plugged in or fully pulled out. Avoid forcing the connection. |
9. User Tips
- For very small SMD components, using the curved tips can provide better contact and stability during measurement.
- When measuring components on a circuit board, ensure the component is isolated from the rest of the circuit to avoid parallel paths that can affect accuracy.
- Utilize the intelligent sorting function for quick checks of component batches, especially when dealing with many similar components.
- Experiment with different test frequencies to get a comprehensive understanding of a component's characteristics, particularly for inductors and capacitors.
10. Warranty and Support
FNIRSI products undergo strict quality inspection before being sent out. We are committed to providing high-quality and reliable testing instruments.
Image: FNIRSI product warranty and quality assurance statement.
If you have any questions, require technical assistance, or need help with your LCR-ST2, please contact our customer support. Refer to your purchase documentation or the seller's website for specific contact details.
11. Product Overview Video
Video: A brief demonstration of the FNIRSI LCR-ST2 Smart Tweezer, showcasing its dual-mode functionality (tweezer and Kelvin clips) and ease of use for various measurements.
