How to choose the sensor grade?

The choice of sensor grade must meet the following two conditions:

1. Meet the requirements of instrument input. 

    The weighing display instrument displays the weighing result after the output signal of the sensor is amplified and A/D converted. Therefore, the output signal of the sensor must be greater than or equal to the input signal size required by the instrument, that is, the output sensitivity of the sensor is substituted for the matching formula of the sensor and the instrument, and the calculation result must be greater than or equal to the input sensitivity required by the instrument.

2. Meet the accuracy requirements of the entire electronic scale.

    An electronic scale is mainly composed of a scale body, a sensor, and an instrument. When selecting the accuracy of the sensor, the accuracy of the sensor should be slightly higher than the theoretical calculation value, because the theory is often limited by objective conditions, such as scales. The strength of the body is a little bit worse, the performance of the instrument is not very good, the working environment of the scale is relatively bad and other factors directly affect the accuracy requirements of the scale. Therefore, the requirements must be improved from all aspects, and economic benefits must be considered to ensure that the purpose is achieved.

3. The matching formula of sensor and meter:

Sensor output sensitivity * excitation power supply voltage * maximum weighing of the scale

Scale division number * number of sensors * sensor range

4. For example: 

A quantitative packaging scale weighing 25kg, the maximum number of divisions is 1000 divisions; the scale body adopts 3 L-BE-25 type sensors, the range is 25kg, the sensitivity is 2.0±0.008mV/V, the arch bridge voltage force 12V; The scale adopts AD4325 meter. Ask whether the sensor used can match the meter.

5. Solution: 

After consulting, the input sensitivity of AD4325 meter is 0.6μV/d, so according to the matching formula of sensor and meter, the actual input signal of the meter can be obtained as:  2×12×25/1000×3×25=8μV/d》0.6μv/d

Therefore, the adopted sensor meets the requirement of instrument input sensitivity and can match the selected instrument.

This article is from Allicdata Electronics Limited which offer electronic components, semiconductors, antennas, capacitors, connectors, diodes, transistors, IC,resistors. For more product information, please go to the website to get it.