Multifunctional anemometer AM-70


АМ-70 is a portable digital measurement device with with autonomous power supply.

Theory of operation

The principle of operation of the AM-70 anemometer is based on determining the air/gas flow rate by measuring the pressure drop arising at the stagnation point in front of a blunt body placed in the air/gas flow. After become measured the pressure drop is converted to air/gas flow velocity. Air velocity measurement result at atmospheric pressure 760 ± 40 mm Hg and ambient temperatures from 0 to 50 ° C can be read directly from the device’s display. In the case of flue gases / emissions with a density close to that of air, the measurement can be also read directly from the screen. In all other cases, corrective calculations must be made.

The air velocity at other parameters of the atmosphere, as well as the velocity of gases, the density of which differs significantly from the density of air, can be determined from the results of measurements using the equation:

\upsilon_{true}=\upsilon_{disp} \cdot \sqrt{ \frac{\rho_0}{\rho} }

  • \upsilon_{true} – true flow speed, \frac{m}{s};
  • \upsilon_{disp} – displayed flow speed, \frac{m}{s};
  • \rho_0 – air density under normal conditions, \frac{kg}{m^{3}};
  • \rho – actual gas density, \frac{kg}{m^{3}};

Design description

The device’s primary sensing element consists of sensor itself and primary signal processing unit (micromanometer). The principle of operation of the sensor equals to working principle of pneumometric tube: coaxial system of two metal tubes where the outer tube diameter is 6 mm and the inner’s one is 2 mm. Minimal length of this pneumometric tube is 250 mm and maximal length is 750 mm. The micromanometer is housed in a metal cylindrical body, which is rigidly connected to the sensor via a pneumatic connector. This case is used as a handle to hold the sensor in the desired position.

The device’s control and indication module is placed inside plastic case and connects to primary sensing element by 1.5 m electrical cable via connector. The connector can also be used to plug a charger in.

Device features

  • ability to measure the velocities of high-temperature gas flows (up to 500 ° C);
  • admissibility of strong dustiness of the gas flow;
  • admissibility of aggressive chemical components in the composition of being measured gas flows;
  • high mechanical strength of the primary sensing element;
  • measurements are performed without any preliminary settings – the procedure for the initial “zero” setting is excluded – the device does it automatically;
  • built-in non-volatile memory to store measurements;
  • optional USB 2.0 device interface support for higher-level system integration;
  • short single measurement time – no more than 1.5 s;
  • automatic powerdown after 15 minutes of inactivity;
  • Measuring range: 0 – 70 m/s;
  • Accuracy: 5%;
  • Resolution: 0.01 m/s;