Good load cells can also be taken from personal scales or kitchen scales. One example is the kitchen scale “IDEENWELT digitale Küchenwaage” from Rossmann, which has a capacity of only 5kg and therefore too small. A bee colony should be able to measure a range between 50-150kg (depending on the weight of the hive).
- The article Rebuild platform scale contains an example of a finished weighing frame including a load cell.
- In the article “Assembly of the scale chassis” Alexander shows how he built the chassis with screen printing plates.
A selection of load cells
|Bosche platform load cell H30A/H40A||15 – 500kg (depending on selection)||approx. 55€ (see saving tip at the end of the article)||?|
|YZC-516||50kg, 100kg und weitere Modelle.||approx. 36$||?|
|200KG Electronic Platform Scale Load Cell Pressure Balanced Cantilever Load Weight Sensor||200kg||approx. 15$ (shipping 2 weeks)||?|
A collection of various load cells is listed in this excel sheet.
The article on the HX711 (A/D converter) contains details on how to connect the load cell to the HX711 and the HX711 to the Raspberry Pi.
- Parallel connection
- Load cells can also be connected in parallel. For example, if several load cells are positioned at the corners. Only identical models should be connected in parallel. Further information on parallel connection of the load cells can be found in this document.
- Ordentliche Kabelführung
- If a cable is bent strongly or under pressure, this can lead to measurement errors. In the case of analog signals, the cable length and shielding/insulation must also be taken into account.
Savings tip for Bosche orders:
1€ discount when ordering with Paypal
-5% discount with coupon code “ONLINE5”.
Total price after that only: 55,39€
Alternative: 4x half bridge load cells
Alternatively there is the possibility to use half bridges weight sensors. One of these is mounted on each corner. You will find all information in this article. However, the measurement results are more likely to differ from the load cells in the table above.
Translated 28.07.2019 by JK