Weighing systems WS 1 / 2 / 5 / 7 kg with Evaluation electronics SYNUS® 6 / 10 / 15


The WS 1 / 2 / 5 / 7 kg weighing systems with built-in infeed and outfeed belts, when used in conjunction with the SYNUS® 6 / 10 / 15 evaluation electronics, combine to form a high-performance checkweigher for determining the weight or completeness of products, and for regulating upstream filling systems. 

These checkweighers are approved for use in legal metrology for average weight control of prepackaged products (AWC) in a number of countries. They have been issued both national type-approval certificates as automatic checkweighers and an OIML R51 certificate. The optional trend controller can be added to regulate existing packaging or filling machines, which contributes significantly to improved efficiency of filling and helps to prevent costly overfill. 

Furthermore, all SYNUS® models offer a variety of COM ports, enabling smooth, centralized integration of SYNUS® checkweighers in existing or new quality assurance systems, for 100% traceability in production monitoring. 

SYNUS® checkweighers can also be connected over Ethernet TCP/IP to the “ProControl for Windows” network QA system from Sartorius, creating an all-inclusive bidirectional link to management functions. 

An integrated printer module can be included for documentation of all relevant operating data. The USBPrint option is a reliable, easy-to-use and – most importantly – broadly compatible option for electronic data transfer without a network.


The checkweigher consists of the following components:

  • Weigher frame with control cabinet
  • Weigh cell
  • Transport system
  • Scanning unit
  • Control electronics
  • Touch guard (optional)
  • Reject or sorting mechanism (optional)
  • Rejected product receptacle (optional)

Weigher frame with control cabinet

Sturdy base frame made of AISI 304 stainless steel (1.4301) with IP65 protection.

The weigher frame supports an adjustable-height traverse member which is attached to the weighing and transport system. The traverse member is form-fitted and friction-locked to the sinusoidal housing side-face by means of a clamping device. Thus the working height can be adjusted over a particularly wide range in increments of 50 mm. Threaded leveling feet are provided for fine adjustment of the height. The display and control unit is built into the control cabinet.

Weigh cell

The product to be weighed is conveyed on infeed, weighing and outfeed belts;

the transport medium is a conveyor belt (weighing belt WS 1 kg also available with circular belts).

The conveyor belt frame consists of polished aluminum sections with a quick-release belt de-tensioning mechanism. Belt pulleys and drive rollers are made of polished aluminum,  Ø 30 mm (WS 1 kg weighing belt: Ø 22 mm).

The quick-release belt de-tensioning mechanism and hinged, removable transport system make it easy to replace belts and load platform. Infeed, weighing and outfeed belts are driven by a 24V maintenance-free EC geared motor.

Power is transmitted by drive belts.


Scanning unit


The scanning unit consists of a reflex light barrier (pulsed, with LED received-signal indicators).

“Monitoring product spacing” (optional)

A second scanning unit can be installed for monitoring product spacing.

“Rejection control” (optional)

An additional light barrier monitors the product flow in order to check for products which are the wrong weight during sorting.