The portable Jerome J505 mercury vapor atomic fluorescence spectroscopy analyzer from Arizona Instrument has an efficient optical cell that requires minimal flow to purge the system, allowing it to run at a low flow rate, minimizing sample dilution. It uses atomic fluorescence spectroscopy to read down to 50 nanograms. It needs no regeneration. It has USB data logging and more than 10 hours’ battery life. It can switch between units of measurement with the push of a button on the test screen. 800/528-7411; www.azic.com.