Easily measure supply and exhaust air flow. The Model APM 151 Electronic Balometer directly measures air flow on its large LCD display and stores up to 100 readings in its non-volatile memory for later analysis. Download data to your computer via APM151C Interface Cable (sold separately). Eliminating time-consuming calculations, this instrument utilizes thermal anemometry technology to display flow in cfm, m³/h or l/s. Light-weight and easy to handle, the Electronic Balometer requires only one person to operate. Standard 2' x 2' hood fits over most standard grills and exhausts. Additional hood expansion kits are sold separately. Each unit includes: APM150 meter, 2' x 2' hood, base, handles, soft carrying case, three AA batteries and calibration data sheet.