Receiving and sending of loadometer loadcells

Receiving and sending of loadometer loadcells

The weighbridge loadcell is ubiquitous in the modern science and technology industry, because it is a sturdy, durable, and reliable electromechanical product. How to connect correctly can ensure the normal use of the instrument, so here is the correct weighing sensor for everyone Connection.

Types of loadometer loadcells:

loadcells can be divided into column type, bridge type, spoke type, cantilever type and so on.

The characteristics of the column loadcells are: low cost, small size, good sealing performance, very suitable for humid environments, strong carrying capacity; its disadvantages are low sensitivity, low stability, and anti-eccentric load and anti-lateral ability within a certain range It is better than the bridge type, and a limit device must be installed.

The characteristics of the bridge laodcells are: high sensitivity, strong stability, can be automatically reset, no limit device is installed; the disadvantage is: within a certain range, it is easy to be affected by the lateral force, and the error is larger than that of the column type.

Spoke loadcell: The loadcell itself has a low height and can withstand large lateral forces; it is resistant to partial load and is insensitive to changes in the force point; it is suitable for scales with low heights such as axle load meters.

The cantilever beam loadcell has the following characteristics: strong anti-eccentric load ability and high accuracy. The sensitivity of the loadcell is basically the same when the loadcell is stretched and compressed, so it is especially suitable for the measurement of simultaneous tension and compression; low profile, small size, light weight , Easy to install and maintain; the disadvantage is that the full-scale accuracy is not high.

Connection method of loadometer loadcell:

Loadometer loadcells generally use bridge QS loadcells, but also column and cantilever beams. Generally, 4-8 loadcells are collected in the junction box, and then connected to the instrument by a main line. loadcells of different manufacturers should be connected according to the instructions. The loadcells wires made by different manufacturers are of different colors. The four wires are positive and negative excitation and positive and negative signals. Generally, the color of the loadcell line is divided into red and black, green and white. Red, black, green and white: Red, white, green, and blue equal sub-marks indicate that V+, V-, S+, and S- are connected to the junction box in turn. According to the structure and distribution of the weighing platform, connect to the junction box 1,2,3,4,5,6,7,8 and label. This is convenient for maintenance.

There are two ways to wire out the load cell: 4-wire and 6-wire. There are also 4-wire and 6-wire wiring for the module or weighing transmitter. Whether to connect 4-wire or 6-wire depends on your hardware requirements. , The principle is: the sensor can be connected to 6 wires but not 4 wires, and the sensors that must be connected to 4 wires must be shorted.

The general load cell is a six-wire system. When connected to a four-wire system, the power line (EXC-, EXC+) and the feedback line (SEN-, SEN+) are short-circuited respectively. SEN+ and SEN- are used for compensating circuit resistance. SEN+ and EXC+ are connected, and SEN- and EXC- are connected. EXC+ and EXC- supply power to the load cell, but due to the line loss between the weigh module and the sensor, the voltage received by the sensor will actually be less than the supply voltage. Each load cell has a characteristic of mV/V. The mV signal it outputs is closely related to the received voltage. SENS+ and SENS- are actually a high-impedance loop in the load cell. The received voltage is fed back to the weighing module. Assuming that EXC+ and EXC- are 10V, the line loss, the sensor is 2mV/V, in fact the maximum signal output by the sensor is ()*2=19mV instead of 20mV. At this time, the load cell will use 19mV as the maximum range, provided that the sensor must feed back the actual voltage to the weighing module through a feedback loop. Short-circuit EXC+ and SENS+, and short-circuit EXC- and SENS- on the load cell. This is limited to occasions where the distance between the sensor and the weighing module is short and the voltage loss is very small, otherwise there will be errors in the measurement.