Accutube brand multi-port averaging pitot tubes are the smart choice when ease of installation, cost-effective operation and accurate flow measurement is a priority. The M1 Series of handheld manometers from Meriam process technologies combines form, fit and function to deliver precision pressure measurement for field, plant or lab use. The M101 delivers +/- 0.10 percent FS accuracy and additional features normally found on higher priced instruments. Pressure limits: (DN) units - 3 x F.S. on high side only or 200 PSI, whichever is less. (GN or AN) units - 3 x F.S. range or 200 PSI, whichever is less. (GN or AN) units - 3 x F.S. range or 200 PSI, whichever is less. Accuracy: no temperature effect over the entire operating range 14F degree to 122 degree F (-10C degree to +50 degree C). Min/Max (M101 only): Displays the MIN and MAX pressures. Hold (M101 only): freezes the pressure measurement on the display, however, the bar graph is still active. Ave (M101 only): Displays a continuous filtered average of the pressure measurements. Temp: displays the internal ambient temperature of the M1 in degree C or degree F. Record mode: The M1 can store up to 240 pressure measurements. Automatic the current value is automatically stored every 5 seconds, for up to 20 minutes. Manual - the current value is stored every time the Units key is pressed, up to 240 times. A green backlight is user activated via the back light key. A red back light is automatically activated during an error/over range condition. To conserve battery life, the M1 will automatically power off after 20 minutes of keypad inactivity. M1 can be calibrated in the field for zero and span. Bar Graph: Horizontal bar for full scale pressure reference (0-100 percent). M101 (specify pressure range) Calibrator All models include the protective red rubber boot, 4 AA batteries, and hard copy of the user ’s manual. 0 - 28.00" H2O Range.