Schematic of experiment wiring 
Relationship plot of Vout/Vin and 1/R 
Straight line fitting at linear region of above plot
Features
Rich in physical concepts
Innovative experimental methods
Comprehensive hands-on training contents
Introduction
The LEEI-15 Apparatus for Measuring Liquid Conductivity is designed with a focus on rich physical principles, innovative experimental techniques, and extensive hands-on training content. It is suitable for basic physics experiments and scientific research involving the measurement of liquid conductivity.
The core component of the apparatus is a mutual-inductive sensor with an empty core, specifically designed for accurate liquid conductivity measurements. This sensor consists of two inductive coils wound on high-permeability iron-based alloy rings made from advanced nanomaterials. It operates with a low-frequency sine signal and uses non-contact inductive electrodes, which eliminates polarization effects around the sensor, ensuring high measurement accurcy.
The LEEI-15 apparatus includes:
- An experimental signal source with a frequency of 2500 Hz
- A mutual-inductive conductivity sensor with two inductive coils wound on high-permeability iron-based alloy rings
- A set of high-precision resistors
- A digital AC voltmeter
- A 1000 ml measuring cup
- Connection wires
Using this apparatus, students can:
1. Understand and demonstrate the working principle of the mutual-inductive liquid conductivity sensor. Learn the relationship between the sensor's output voltage and the liquid's conductivity, and explore key physical concepts such as Faraday's law of electromagnetic induction, Ohm's law, and the principle of transformers.
2. Calibrate the mutual-inductive liquid conductivity sensor using precise standard resistors.
3. Measure the conductivity of a saturated saline solution at room temperature.
4. Optionally, determine the relationship curve between the conductivity and temperature of a saltwater solution.
The instruction manual provides detailed experimental configurations, theoretical principles, step-by-step guidance, and examples of experimental results. For more information, please click Experiment Theory and Contents to explore this apparatus further.
Specifications
| Description | Specifications |
| Experiment power supply | AC sine wave, 1.700 ~ 1.900 V, continuously adjustable, frequency 2500 Hz |
| Digital AC voltmeter | range 0 -1.999 V, resolution 0.001 V |
| Sensor | mutual inductance consisting of two inductive coils wound on two high permeability iron-based alloy rings |
| Precision standard resistance | 0.1 Ω and 0.9 Ω, each 9 pcs, accuracy 0.01% |
| Power consumption | < 50 W |
Parts List
| Item | Qty |
| Main electric unit | 1 |
| Sensor assembly | 1 set |
| 1000 mL measuring cup | 1 |
| Connection wires | 8 |
| Power cord | 1 |
| Instruction manual | 1 (Electronic version) |
Schematic of experiment wiring
Relationship plot of Vout/Vin and 1/R
Straight line fitting at linear region of above plot
