The DUSPOL digital is a digital true RMS voltage and continuity tester with resistance and frequency range. This voltage tester is suitable for areas such as electrical engineering, industry, maintenance, service (troubleshooting), and photovoltaics. Reliable measurement results are ensured by ISO calibration. ISO calibration is necessary when the measuring device is used for measurement tasks in an environment certified according to ISO 9001. An ISO certification is also helpful and often a requirement for experts, acceptance points, or testing laboratories.