How to read a water meter and which one indicates tons

The first 4 digits of this water meter are black, the 5th digit is red, and there are only 3 red pointers. The red pointer next to the "× 0.1" means "with the pointer pointed at the number × 0.1 tons"; red pointer next to the "× 0.01" means The "×0.01" next to the red pointer means "the number pointed to by the pointer ×0.01 tons".

Expanded information:

Minimum flow rate (Q1): requires that the meter's display value meets the maximum allowable error of the minimum flow rate.

Boundary flow (Q2): appear in the common flow Q3 and minimum flow Q1, the flow range is divided into a specific maximum allowable error "high zone" and "low zone" two zones of flow.

Common flow (Q3): the maximum flow rate under rated operating conditions. In this flow rate, the water meter should work properly and meet the maximum allowable error requirements.

Overload flow (Q4): the water meter is required to meet the maximum permissible error requirements for a short period of time, and then in the rated operating conditions can still maintain the measurement characteristics of the maximum flow.

Pressure loss (Δp): the head loss caused by the presence of the meter in the pipe at a given flow rate.

The internal structure of the traditional water meter can be divided into three main parts from the outside to the inside: the shell, the sleeve and the inner core. Shell is cast iron, water from the inlet out of the shell through the lower ring space, which is called the "lower ring room". In this annular space above the "upper ring chamber" and the water outlet connected. The bottom of the sleeve has a filter with small holes to filter out debris in the water.

The side of the sleeve has two rows of circular holes, the location of the holes and the shell of the upper and lower annular chamber of the opposite, obviously, the lower row is the water inlet holes, the upper row is the water outlet holes. Particularly noteworthy is that both rows of holes are punched diagonally along the tangent direction of the circle. Note that the top and bottom rows of holes are in opposite directions.

Water from the lower row of holes along the tangential direction of flow in, is bound to form a rotating water flow, which is very important for the work of the water meter. The inner core is divided into upper, middle and lower three layers, seen from the glass window is the upper layer, only the pointer and dial. In fact, the most critical is the lower layer, which has a plastic wheel, the wheel has many plastic blades, called "impeller".

By measuring principle

Divided into speed type water meter and volume type water meter.

(1) speed type water meter: installed in a closed pipe, consisting of a moving element, and by the speed of water movement directly to the power speed of the water meter.

Typical speed type water meter has rotary wing type water meter, screw wing type water meter. Rotary wing type water meter and there is a single beam water meter and multi-beam water meter.

(2) volumetric water meter: installed in the pipeline, by a number of being filled and discharged fluid known volume of the chamber and by virtue of the fluid-driven mechanism composed of water meter, or simply quantitative discharge water meter.

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