3810DSII Type:Low-cost Mass Flow Meter with Display

3810DSII Type:Low-cost Mass Flow Meter with Display

3810DS II is a mass flow meter with a built-in display using a time-tested flow sensor. The 3810DS II displays total flow in addition to instantaneous flow, which is an improvement on the previous model 3810DS. Just like the 3810DS, the 3810DS II is also available with flow sensor and precision needle valve built into one piece.

  • Features

    ・ Precision needle valve for controlling and monitoring very low flow rates
    ・Two alarm outputs for flow monitoring
    ・Analog output for instantaneous flow and pulse output for total flow
    ・Compact and lightweight
    ・The display is built in and the meter only requires connection to a 24-VDC power supply.
    ・The meter measures mass flow and directly reads the flow.
    There is no need for flow correction calculations based on tem-perature and pressure.

    Standard Specifications


    Thermal sensor

    Flow range (N2 equivalent)

    10 SCCM–20 SLM

    21–100 SLM


    Within ±2% F.S. at 25

    Within ±3% F.S. at 25

    Operating pressure

    0.0–0.5 MPa (G)

    Proof pressure

    1.0 MPa (G)

    Allowable ambient temperature


    Temperature coefficient

    ±0.2% F.S./ (15–35)

    Materials of parts in

    Body: SUS303, PTFE

    contact with gases

    Sealing: FKM


    Option: Neoprene

    Connection end

    Standard: Rc 1/4 (Ask us for other sizes.)

    Power supply

    24 VDC ±5%, 100 mA (option: AC adapter)

    Flow output signal

    1–5 V, 4–20 mA (Select when ordering.)

    Event output

    2 × NPN open collector output Maximum rating: 30

    VDC, 50 A

    *Cable connection
    Connector: 3810DS II end: HR10A-7R-6P (Hirose Electric) Cable end: HR10A-7P-6S (Hirose Electric)

    *A conversion cable for the previous model 3810DS is available.
    Specifications relating to the flow range (e.g., flow range, accuracy and repeat-ability) are expressed in N2 or air equivalent. The product will be built with the primary pressure of 300 kPa or less and the secondary side open to the atmos-phere. For details on the pressure requirements, ask us.


    What is a thermal mass flow meter?

    Thermal mass flow meter is an accurate, easy-to-install, low pressure drop type flow meter. It is suitable for flow measurement and control of dry gas applications. Thermal mass flow meters are also available through the Gas Type Reference link application. The mass flow meter observes the cooling effect on the heated transducer as the air flow changes. Compared to other gas flow measurement equipment, the result is a high level of accuracy at a low cost.


    • High accuracy
    • Wide range of flows, including low flows
    • Simple and durable structure
    • Easy to install and maintain
    • Flexible connection of flow meters for flow control
    • Various process connections
    • Regulation ratio 100: 1
    • Low pressure drop on the flow meter
    • Provide convenient signal output


    Thermal mass flow meter principle

    Thermal mass flow meters use the thermal properties of a fluid to measure the motion of the fluid in a pipe or tube. In a thermal energy flow meter, the measured heat is applied to the heater of the sensor. A certain amount of energy is lost during the flow, and as the flow increases, more energy is lost. The energy lost by the sensor depends on the thermal characteristics of the fluid and the sensor design. The hot-pressing characteristics of a fluid may change with temperature and pressure, although these changes are usually irrelevant in most applications. Since heat flow measurement does not depend on the temperature or pressure of the fluid, a thermal energy flow meter can be used to estimate the mass flow of the fluid.

    In other words, in most applications, the nature of a fluid may depend on its composition. For these applications, different components of the fluid may interfere with the heat flow size during actual operation. Therefore, it is important for a thermal mass flow meter provider to understand the composition of the fluid so that the appropriate normalization factors can be processed to accurately determine the flow. Due to this limitation, thermal mass flow meters are often used to measure the flow of pure gases. Manufacturers can provide appropriate standardized information for other gas combinations, but the accuracy of a thermal mass flow meter depends on whether the actual gas mixture is the same as the gas mixture used for standardization purposes.