Product Description & Key Specifications

What it is

This is an analog moving-coil galvanometer mounted on a desk stand, designed for laboratory use. In this case:

• Scale: 30-0-30 (means the pointer can deflect 30 divisions in the positive direction, 0 at centre, 30 in the negative)

• Sensitivity: 20 µA per division (i.e., every division on the scale corresponds to 20 microamperes of current)

• Colour / finish: Black (in the listing: “Black … desk stand analog 30-0-30 (20µA/Div) moving coil galvanometer (Black)”)

• Mounting: Desk stand type (i.e., has its own base/stand so you can place it on a bench)

• Usage: For measuring small DC currents in laboratory experiments (physics labs, engineering labs) using a moving-coil type galvanometer.

Additional Specification Highlights (from available data)

From the MR-100 variant:

• Case: ABS plastic (in some versions)

• Accuracy: ±2% of full-scale deflection (F.S.D) in some models.

• Dimensions: Example listed for MR-100: about 100mm × 100mm × 140mm.

• Scale length: In one listing ~80 mm approximate for the 30-0-30 (20µA/div) model.

• Weight: Example ~300 g approx for a particular version.

• Mounting style: Front terminal, stand-type base etc.

What “30-0-30 (20 µA/Div)” means

• The “30-0-30” indicates the full-scale deflection is ±30 divisions from the centre zero.

• With “20 µA/Div”, one division equals 20 microamperes. So full deflection (30 divisions) corresponds to 30 × 20 µA = 600 µA (0.6 mA) in that direction, and similarly in the negative direction.

• The moving-coil galvanometer works by the coil in a magnetic field being deflected proportionally to current

Construction / Features

• Moving coil type: a fine coil wound on a frame, suspended in a magnetic field, with a pointer that deflects when current passes. The deflection is proportional to current (for small currents).

• Desk stand: Means the instrument is mounted such that it can stand on a bench, making it convenient for experiments.

• Black-colour finish: This particular listing emphasises “Black” in the description (e.g., “…Galvanometer (Black)”).

• Portable / compact for lab use: Some listings mention “portable and compact” design.

✅ Applications & Use-Cases

• Ideal for measurement of small DC currents in physics/engineering laboratory experiments (for example: ● Wheatstone bridges, ● null/detection experiments, ● demonstration of current flow).

• Educational labs: Suitable for school/college practicals where students need to see current deflection. Example listing: “School & Colleges Lab experiment – galvanometer – for science lab.”Research or prototyping where measuring micro‐ampere level currents is required.

• Demonstrations of principles of electromagnetic measurement devices: useful since the scale is symmetric (30-0-30) and shows positive/negative deflection, which helps illustrate direction of current.

⚠️ Things to Check / Consider Before Buying or Using

• Range & sensitivity: Ensure the 20 µA/div suits your experiment. If your current flow is much higher or much lower, either you’ll not use much of the scale or you risk saturation.

• Accuracy: Some models list ±2% F.S.D (full scale deflection) as accuracy. If you need higher precision, check spec sheet. (For example: listing mentioned “Accuracy: ±2 F.S.D.”)

• Scale readability: Since it’s analog, check that the scale divisions are clear, pointer is sharp, and parallax error is minimised (some units may have anti-parallax mirror). One listing even mentions “anti-parallax mirror” for pointer reading.

• Mounting stability: Desk stand should be stable so that vibrations or bench movement don’t affect readings.

• Coil resistance & circuit compatibility: Galvanometers typically have low coil resistance; ensure your circuit can safely connect to it without loading or altering measurement significantly.

• Direction of deflection: The 30-0-30 gives you both positive and negative deflection; your experiment should permit centred zero, or you might need modifications.

• Durability: Since moving parts are involved (coil, springs, bearings), check build quality. Some models use ABS plastic case; while adequate, might be less robust than metal. Extract: “Case: ABS Plastic …”

• Calibration / zeroing: Before use, ensure pointer is truly at zero when no current passes; if not, you may need to adjust or compensate.