Weighing technology

In the computer age, we rely exclusively on digital weighing technology. In contrast to analog technology, digital weighing technology allows the measurement signals to be intelligently filtered in advance and the measured values to be reliably transported over longer distances.
Two fundamentally different measurement technologies are used in our platform scales to calculate the weight loss during gravimetric dosing: Pesa string technology ( PESA )and the strain gauge principle ( DMS ).


Our scales, enclosed in solid stainless steel housings, are available in four sizes, each with different nominal loads. The plug connections are located at the rear and are positioned at the optimum height to minimize the bending radius of the cable harness.

The measuring technology used is usually product or customer-specific, although the platform scales do not differ externally.
For larger throughputs (> 10 kg/h), a resolution of 10 g is usually sufficient, which is achieved with our standard strain gauge measuring cells.
For smaller throughputs (< 10 kg/h), we recommend our PESA or high-resolution strain gauge scales.


What makes our scales and dosing software so unique

The measurement technology can be replaced without rewiring. For example, a PESA scale can be replaced by a strain gauge scale and vice versa. The EasyControl dosing software identifies each individual scale on the bus and switches to the appropriate protocol individually and independently.


New*** Scale technology with EtherCAT

SmaDoTec opens a new chapter in the development of innovative scale technology. Until now, the scales were usually connected to the RS485 field bus in a star configuration. It is now possible to operate the aforementioned strain gauge scales optionally on the EtherCAT bus.

What are the advantages of EtherCAT?

The RS485 fieldbus was developed in the last century and has undergone little further development. It is still based on the technology and specification from back then and is only used by most modern devices for compatibility reasons, but generally without utilizing all the advanced possibilities.
The EtherCAT bus system is faster, more flexible to wire, easier to configure and more cost-effective than conventional fieldbus systems. At the same time, considerably higher transfer rates are achieved over longer distances with greater safety and less susceptibility to interference. Furthermore, there are extensive diagnostic options that were difficult to access remotely in the past with conventional fieldbus systems.
EtherCAT is tried and tested and has proven itself in series applications for years.


Optionally all scales are also available for ATEX zones, on request also with ATEX connector sets.

Plattform scaleWidth, Depth [mm]
Height [mm]
TypeNominal load [kg]
Bus type
PS3-P30/75/150
300
150PESA30/75/150RS485
PS3-SU50/75/120/200300
150
DMS50/75/120/200
RS485
PS3-SHRU50/75/120/200300
150DMS-HR50/75/120/200RS485
PS3-SL50/75/120/200300
150DMS-HR50/75/120/200
EtherCAT
PS4-P30/75/150
400150PESA30/75/150RS485
PS4-SU50/75/120/200400150DMS50/75/120/200
RS485
PS4-SHRU50/75/120/200400150DMS-HR50/75/120/200RS485
PS4-SL50/75/120/200
400150DMS-HR50/75/120/200
EtherCAT
PS6-P300/600600150PESA300/600RS485
PS6-SU300/600600150DMS300/600RS485
PS6-SHRU300/600600150DMS-HR300/600RS485
PS6-SL300/600
600150DMS-HR300/600
EtherCAT
PS8-SU400/600/1000800150DMS400/600/1000RS485
PS8-SHRU400/600/1000800150DMS-HR400/600/1000RS485
PS8-SL400/600/1000
800150DMS-HR400/600/1000
EtherCAT

The Pesa strings technology

In Pesa string technology, the tension of the vibrating string is influenced by the introduced mass, which changes the vibration frequency of the string. The weight is calculated from the change in vibration frequency. ( Source PESA – Weighing Systems, PESA Waagen AG )

Strain gauge

A strain gauge is a sensor whose electrical resistance changes with the applied force. The change in resistance is accompanied by a change in the measuring voltage, which can be read out via a measuring amplifier and an analog-to-digital converter.