Gauhati University Tender

Laboratory Equipments/Experiment set ups

Experiment Name: To verify the law of Malus for Plane Polarised Light Technical specifcations: i. Light Source: - LED: 532 nm or 635 nm (±2 nm stability), 1–5 mW adjustable output. - Unpolarized (extinction ratio >500:1). - Collimated beam (divergence ≤0.5 mrad); Qty-1 ii. Polarizers- Glan-Thompson or polymer film. - Extinction ratio ≥10³:1 @ operating wavelength. - Mounted in Ø50 mm rotation holders.; Qty-2 iii. Rotation Stage- Motorized analyzer rotation (0.05° resolution). - Accuracy: ±0.1°. - Range: 0°–360° (continuous).; Qty-1 iv. Photodetector- Silicon photodiode (400–1100 nm). - Linearity: R² ≥0.999 (0.1 μW–5 mW). - Digital readout: 0.1 μW resolution.; Qty-1 v. Optical Bench-- Anodized rail (≥60 cm) with kinematic mounts. - Vibration-damping feet.; Qty-1

Experiment Name: To determine thespecific rotation of sugar solution using polarimeter Technical Requirements a.Core Instrument i. Light Source- - Sodium D-line (589.3 nm) or tunable LED (±2 nm stability). - Output stability: <±0.2% drift/hour. Ii. Polarizer/Analyzer- Glan-Thompson prisms or high-grade polymer film. - Extinction ratio ≥10,000:1 at 589 nm. iii. Rotation Stage- Motorized with 0.001° resolution.- Accuracy: ±0.005°.- Range: -90° to +90°. iv. Sample Cell-- Borosilicate glass tubes with precision ground ends. - Path lengths: 0.5 dm, 1.0 dm, 2.0 dm (±0.01 dm tolerance). - Temperature-controlled jacket (5–50°C ±0.1°C). v. Detector- Photomultiplier tube (PMT) or low-noise photodiode. - Linearity: R² ≥ 0.999 over 0.1 μW–5 mW range vi. Enclosure- Light-tight with vibration damping. - Internal black anodized surfaces. b.Measurement Specifications i. Specific Rotation: Range: -180° to +180° Resolution: 0.001° Accuracy: ±0.01° ii. Concentration-Range: 0.01–0.5 g/mL (sucrose in water) Detection limit: 0.001 g/mL iii. Temperature Control-Stability: ±0.1°C at 20°C (standard condition)