Conductivity tester is mainly used to detect conductivity, resistivity, thermal conduction effect, heat dissipation effect, heat treatment condition, purity, etc. of non-magnetic colored metals such as copper and aluminum… It has a self-compensation function . The conductivity measurement results are automatically corrected to a value of 20°C. The normal working environment temperature is 0°C to +50°C and the relative humidity is 0 to 95%.
Conductivity has a great relationship with temperature. The conductivity of metals decreases as the temperature increases. The conductivity of semiconductors increases as the temperature increases, and within a certain temperature range, the conductivity can be approximated as being proportional to temperature.
To compare the conductivity of substances under different temperature conditions, a common reference temperature must be defined.
The correlation between conductivity and temperature can often be expressed as: the slope of the graph of conductivity versus temperature.
Appendix 1: Reference table of conductivity values and temperature coefficients for common materials.
| Metal | Electrical Conductivity（20℃） | Temperature coefficient (parameter)（20℃） | |
| %IACS | MS/m | ||
| Soft copper | ≥100 | ≥58 | 0.0038 |
| Hard Copper | ≥97 | ≥56.26 | 0.0038 |
| Soft aluminum | ≥61 | ≥35.4 | 0.0040 |
| Hard Aluminum | ≥59.5 | ≥34.51 | 0.0040 |
| Gold | ≥70.7 | ≥41 | 0.0034 |
| Silver | ≥108 | ≥62.5 | 0.0038 |
| Brass | ≥25 | ≥14.5 | 0.0020 |
| Bronze Aluminum | ≥9 | ≥5.2 | 0.0005 |
| Titanium | ≥3.6 | ≥2.08 | |
| Lead | ≥7.8 | ≥4.5 | 0.0039 |
| Tungsten | ≥15 | ≥8.7 | 0.0042 |
| Zinc | ≥30 | ≥17.4 | 0.0037 |
| Nickel | ≥22 | ≥12.8 | 0.0060 |
| Magnesium | ≥38 | ≥22 | 0.0040 |
| Average value | 0.0026 | ||
Appendix 2: Technical Specifications for the Sigma Conductivity Tester
| Product Model Design | Sigma 2008 | Sigma 2008B,C |
| Operating frequency | 60KHz sine wave | 60KHz and 500KHz |
| Electrical conductivity measurement range | From 0.8% IACS to 110% IACS, 0.46 MS/m to 64 MS/m or resistivity from 0.01560 to 0.02170 ohm·mm²/m. | |
| Resolution | 0.01% SIGC (when less than 51% SIGC); 0.1% SIGC (within the range of 51% SIGC to 110% SIGC) | |
| Measurement accuracy | ±0.5% (when the temperature is 20°C); ±1% (when the temperature is between 0°C and 40°C) | |
| Lifting Effect | Probe offset is 0.5mm | |
| Temperature measurement | 0°C to +50°C (with accuracy up to 0.5°C) | |
| Automatic compensation function | The conductivity measurement result is automatically corrected to the value of 20°C | |
| Normal operating environment | Temperature from 0°C to +50°C, relative humidity from 0% to 95% | |
| Show | Large, backlit LCD screen displays several important parameters simultaneously. | |
| Power supply | Three AA (Ni-MH) rechargeable batteries or three 1.5 volt AA alkaline rechargeable batteries can work continuously for more than 16 hours (without backlight). | |
| Probe | The Type A machine is equipped with a 14 mm diameter probe and a working frequency of 60 KHz. Type B and C machines are equipped with a 14 mm diameter probe with a working frequency of 60 KHz and an 8 mm diameter probe with a working frequency of 500 KHz. | |
| Read storage | Can save 500 measurement data files | |
| PC communication method | RS232 serial port | |
| Mainframe Weight | 0.5KG (including battery) | |
| Mainframe size | 220mm × 95mm × 55mm | |
| Instrument Casing | Waterproof and highly impact resistant engineering plastic housing | |
| Packaging and Protection | Portable case in waterproof and highly impact-resistant aluminum alloy, equipped with instruments, probes, communication cables, operating manuals, conductivity standard blocks, chargers and instrument holders | |
| Attachments | Three random conductivity test pattern blocks are included and more pattern test blocks are available for user purchase. | |
