Weighing - Sample weighing is a fundamental laboratory process. By interfacing a high-performance analytical balance with a robotic platform, Zinsser has developed automated and semi-automated solutions for the weighing of liquids and powders.
Applications	Routine weighing of liquids Routine weighing of powder QC Dissolution Sample/reagent preparation Compound library redistribution

Zinsser weighing platforms start with a high-performance Sartorius analytical balance that is interfaced with the robotic platform. Ideal for automation, the Sartorius GENIUS® is 40% faster than other balances, not sensitive to noise and distortion, has a resolution of 0.01 mg, 210 g taring range, and ionization. The balance is enclosed in a draft shield that is automatically opened and closed by the system.

Fully-automated weighing. The robotic platform can perform fully automated weighing operations for liquids and free-flowing powders. The robotic arm is used to move vials to and from the balance. A typical operation would consist of these steps:

• Move vial to bar code scanner and record ID.
• Move vial to balance and record tare.
• Move vial to deck and perform liquid or powder addition.
• Move vial back to balance and record weight.

Fully-automatic target weighing with powders. It is possible to configure a Zinsser REDI platform to perform automatic powder dispensing in combination with weighing and interactive software control to allow preparation of samples with pre-determined weights. This is accomplished with a REDI-VARIX tool which can automatically dispense varying amounts of powder combined with Zinsser WeighWizard software. The WeighWizard software stores a database of volume/mass calibration curves for different materials, and accesses this information when presented with a target weight. A 3-step reiterative process will produce the final target weight in 2-3 minutes, including all weighing and taring steps.

Semi-automated target weighing. This is a solution that involves interaction between the robotic platform and the operator. This is particularly useful for weighing non-flowing powders or sticky compounds that require a human operator to move the sample. Even under these conditions, it is still possible to utilize the robotic platform to automate portions of this process.

• Move vial to bar code scanner and record ID.
• Move vial to balance and record tare.
• Operator adds a small amount of compound to the vial.
• A simple user interface with a progress meter provides feedback to the operator to add more compound.
• The operator continues to add compound using the interactive software as a guide until the target weight is reached.

Automated capping/decapping. The optional automated capping on-deck system can be added for complete hands-off weighing operations for vials. The capper/decapper reads the vial barcode at the same time as the capping operation.

Photo gallery. Click these pictures to open a larger version in a new window.

Calli with Sartorius balance	Calli with Sartorius balance	Sartorius Genius balance	Automatic capper/decapper with barcode scanner
Calli XXL for weighing of vials and microtubes, liquid handling, vortexing, and automatic capping/decapping	Robot arm presenting labware to bar code scanner	Calli-Plus for taring and weighing of reactors, weighing and storing substances	WeighWizard software screen showing tare weights and target weights