1. Introduction
This manual provides detailed instructions for the setup, operation, and maintenance of your AmScope B120C-R Binocular Compound Microscope. Designed for teaching demonstrations, clinical examinations, and laboratory applications, this microscope is an ideal tool for students and professionals in biology and medical fields. It features dual power with USB-C charging and rechargeable AA batteries, enhanced LED lighting, a centerable condenser, and Siedentopf head adjustments for comfortable viewing.
2. Key Features
- NEWLY DESIGNED: The B120C-R Binocular Compound Microscope includes updated quality-of-life features such as dual power with Universal USB-C to USB and included AA rechargeable batteries.
- MAGNIFICATION: 40X to 2500X expanded magnification range using high-quality, color-coded objective lenses, and 10X and 25X eyepieces for six unique settings ideal for viewing cellular structures and microorganisms.
- AFFORDABLE: An economical microscope for students and professionals, the B120C-R packs high-quality optics and refined mechanics into a compact form.
- FEATURES: The Siedentopf binocular head has a comfortable 30° incline, can be rotated 360°, and provides interpupillary and dioptric adjustments to suit any user. Students and professionals alike will appreciate the 3-axis mechanical stage with low-position controls, and the coaxial coarse and fine focus for their ergonomics and efficiency.
- LED LIGHTING: The bright, daylight-balanced LED illumination uses our specialized fly-eye lens for improved uniformity and contrast, and the centerable condenser assures proper alignment.

Image showing key features of the microscope, including 30-degree inclination, 360-degree rotation, 10X and 25X eyepieces, 2-layer mechanical stage, 40X to 2500X magnification, and LED sub-stage lighting.
3. What's in the Box
- One binocular microscope head
- One microscope body
- Four objective lenses: 4X, 10X, 40X, 100X
- One pair 10X eyepieces
- One pair 25X eyepieces
- One blue color filter
- One dust cover
- One sample immersion oil
- 3x AA rechargeable batteries
- Type-C to USB cable
4. Setup Guide
4.1 Unpacking and Assembly
- Carefully remove all components from the packaging.
- Place the microscope body on a stable, flat surface.
- Attach the binocular head to the top of the microscope body, securing it with the set screw if present.
- Insert the 10X eyepieces into the ocular tubes of the binocular head. For higher magnification, insert the 25X eyepieces.
- Screw the objective lenses (4X, 10X, 40X, 100X) into the revolving nosepiece in increasing order of magnification.
4.2 Powering the Microscope
The AmScope B120C-R microscope supports dual power options: USB-C and rechargeable AA batteries.
- Battery Power: Insert the three included AA rechargeable batteries into the battery compartment. Ensure correct polarity.
- USB-C Power: Connect the provided USB-C to USB-A cable to the microscope's USB-C port and to a compatible USB power source (e.g., wall adapter, laptop/PC, power bank). The microscope can be powered and batteries charged simultaneously.
- Important Note: Never plug in external power when non-rechargeable (normal) AA batteries are installed in the microscope. Only use rechargeable batteries or no batteries when connecting via USB-C.

Image illustrating the two-way power supply, showing rechargeable batteries and a USB-C cable connected to a laptop for power.
Video demonstrating the USB-C charging capability and power options for the AmScope B120C-R microscope. This video is provided by the seller.
5. Operating Instructions
5.1 Adjusting the Binocular Head
- Interpupillary Adjustment: Adjust the distance between the eyepieces to match your eye spacing by gently pushing or pulling the ocular tubes until a single circular field of view is observed.
- Diopter Adjustment: If you have vision differences between your eyes, use the diopter adjustment ring on the left ocular tube to compensate. Focus with your right eye first (using the coarse and fine focus knobs), then close your right eye and adjust the diopter ring with your left eye until the image is sharp.
- Rotation: The Siedentopf head can be rotated 360° for comfortable viewing by multiple users or for sharing observations.

Image detailing the adjustable 30-degree inclination and 360-degree rotation of the Siedentopf binocular head, along with eyepiece adjustment.
5.2 Placing and Focusing a Specimen
- Turn on the LED illuminator using the power switch. Adjust the brightness using the dimmer control.
- Place a prepared specimen slide onto the mechanical stage, securing it with the stage clips.
- Rotate the nosepiece to select the lowest power objective lens (e.g., 4X). Ensure it clicks into place.
- Use the coarse focus knob to bring the specimen into approximate focus.
- Use the fine focus knob for precise focusing.
- Use the X-Y translation knobs on the mechanical stage to move the specimen and view different areas.
- To increase magnification, rotate the nosepiece to the next objective lens. Minor fine focus adjustments may be needed.
- For the 100X objective, a drop of immersion oil must be applied to the slide before lowering the objective into the oil.

Image illustrating the four magnification levels (40X, 100X, 400X, 1000X) and how 25X eyepieces expand maximum magnification to 2500X.

Image showing the 2-layer mechanical stage for smooth specimen movement and the coaxial coarse and fine focus knobs for enhanced ergonomics.
5.3 Adjusting Illumination
- The LED illuminator provides bright, daylight-balanced light.
- Use the dimmer control to adjust the light intensity for optimal viewing.
- The Abbe condenser with iris diaphragm can be adjusted to control the amount and angle of light reaching the specimen, improving contrast and resolution. Ensure the condenser is centered for best results.
6. Maintenance and Care
- Cleaning Lenses: Use only specialized lens cleaning paper and lens cleaning solution. Gently wipe the lens surfaces. Never use abrasive materials or harsh chemicals.
- Cleaning Body: Wipe the microscope body with a soft, damp cloth. Avoid getting moisture into electrical components.
- Storage: When not in use, cover the microscope with the provided dust cover to protect it from dust and debris. Store in a cool, dry place.
- Immersion Oil: After using the 100X objective with immersion oil, clean the objective lens immediately to prevent oil from hardening.
- Battery Care: If storing the microscope for an extended period, remove the rechargeable AA batteries to prevent potential leakage.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No illumination | Power switch off, batteries low/dead, USB-C cable disconnected. | Turn on power switch, charge/replace batteries, ensure USB-C connection is secure. |
| Image blurry/out of focus | Incorrect focus knob usage, objective not clicked into place, dirty lens. | Use fine focus, rotate nosepiece until objective clicks, clean objective/eyepiece lenses. |
| Dark or uneven field of view | Condenser not centered, iris diaphragm closed too much, low illumination. | Center the Abbe condenser, open iris diaphragm, increase illumination brightness. |
| Specimen not moving smoothly on stage | Stage mechanism dirty or damaged. | Clean stage, if problem persists, contact customer support. |
8. Specifications
- Optical System: Finite-conjugate
- Mechanical Tube Length: 160mm
- Head: Binocular, 30° incline, 360° rotatable
- Interpupillary Adjustment: Siedentopf, 55-75mm
- Ocular Diameter: 23mm
- Eyepieces: 10X, 25X
- Objective Lenses: DIN standard Achromatic 4X, 10X, 40X, 100X
- Objective Parfocal Distance: 45mm
- Objective Mounting Thread: RMS 20.32mm
- Objective Turret: Quadruple
- Focusing System: Coaxial coarse and fine focus
- Fine Focusing Precision: 0.002mm
- Stage Design: Double-layer with caliper
- Stage Dimensions: 116mm x 125mm
- X-Y Translation Range: 70mm x 25mm
- Transmitted Illumination: Variable-intensity 1W LED, fly-eye lens
- Condenser: NA1.25 Abbe condenser with iris diaphragm
- Sub-stage Condenser-holder: rack and pinion, centerable
- Power: Type-C to USB 5V/1A
- Dimensions: 10.3" x 5.4" x 16.1" (26.2cm x 13.8cm x 40.1cm)
- Material: Metal, Plastic
- Color: Blue
- Real Angle of View: 45 Degrees
- Magnification Maximum: 2500 x
- Compatible Devices: Laptop, Personal Computer
9. Warranty and Support
For warranty information and technical support, please refer to the official AmScope website or contact their customer service directly. Keep your purchase receipt for warranty claims.
Visit the AmScope Store: AmScope Official Store





