There is an immediate need for aerosol measuring sensors to monitor the size and concentration of DNA strand aerosols in PCR systems. We evaluate the performance of a previously developed small aerosol sensor for its potential use as a component in measuring DNA strand aerosols in PCR system chambers. A detailed derivation of the working principle is presented along with the principles used to determine the dimensions of the stages and the operational parameters. After characterizing the aerosolized DNA strands, experiments were conducted to identify their relationship with measured currents. The experimental results indicate that for aerosolized Escherichia coli DNA strands, the sensor is capable of measuring concentrations from 102 cm–3 to 105 cm–3 (from 103 cm–3 to 105 cm–3 for particles smaller than 102 nm) and sizes from 100 bp to 1000 bp. There was a slight difference between the results of the sensor and its theoretical model. The sensor exhibited good sensitivity to different concentrations and can detect every 150 bp of strands, indicating its effectiveness in monitoring ultrafine DNA strand aerosols for PCR systems and other applications.