HT Instruments HT39 TRMS Digital Multimeter up to 4000 Counts with RS232 Interface HT39 model perform basically AC/DC TRMS voltage measurements, DC/AC TRMS current measurements in totally autorange. AC voltage and current Peak values such important in industrial environments. This model is also provided with RS-232 interface for PC connection and real-time visualization of electrical parameters. In this way (with optional Windows software) recordings values with selectable sample period are possible. The meter is designed for achieve CAT III 1000V and CAT IV 600V, with Class 2 protection (double insulation), according to EN 61010-1 safety Standard and have a internal fuse protection on input current. HT39 is fitted in a rubber holster for protection by hurts and a practical support for easy to use in horizontal position. HT39 have a large LCD 4 digit display (4000 counts) an analogical bargraph and backlight features for easy readings also in dark environments and each measurement function can be selected with a rotate selector at 10 positions. Other features are MAX and MIN measurements, HOLD function, manual range selection and Relative measurements. An Auto Power Off function is integrated to preserve the internal battery after 30 minutes of idleness.