The Idspot Galvanometer is a specialized light-spot reflecting instrument designed for detecting and measuring minute electrical currents ($nA$ or $\mu A$). Using an internal optical mirror and a projected light beam, it provides a parallax-free, high-precision reading that standard needle meters cannot match.
| Feature | Details |
| Product Type | Mirror-Type Reflecting Galvanometer |
| Current Sensitivity | $0.1 \mu A/\text{mm}$ to $1.0 \mu A/\text{mm}$ (Adjustable) |
| Scale Length | 150mm - 200mm (Translucent Glass Scale) |
| Internal Resistance | $100 \Omega$ to $1000 \Omega$ (Standard models) |
| Light Source | 6V / 10W Integral Halogen or LED Projection Lamp |
| Suspension Type | Taut-Band / Torsion Ribbon (Frictionless) |
| Power Input | 220V - 240V AC (For internal light source) |
Optical Beam Projection: Instead of a physical needle, it uses a sharp "Light Spot" (Idspot) projected onto a frosted glass scale, eliminating mechanical friction and mass-inertia.
Parallax-Free Reading: The light spot is projected directly onto the scale, ensuring the highest reading accuracy from any viewing angle.
Taut-Band Suspension: The moving coil is suspended by a fine gold or bronze ribbon, providing extreme sensitivity and preventing "sticking" issues found in pivot-type meters.
Built-in Transformer: Includes an internal step-down transformer to power the projection lamp directly from standard AC outlets.
External Zero Adjustment: A smooth-action knob on the top or side allows for precise centering of the light spot before measurements.
Bridge Balancing: Perfect for Wheatstone Bridge and Potentiometer experiments where a "Null Point" must be found.
Electromagnetic Induction: Detecting small induced currents in physics experiments.
Semiconductor Testing: Measuring leakage currents in diodes and transistors.
Calibration Labs: Used as a reference instrument for calibrating less sensitive ammeters.