Mettler Toledo Balances

Revolution drives a Mettler Toledo balance as a scheduled instrument. The reason to have one in a cell is usually not weighing for its own sake — it is gravimetric verification: confirming by weight that a dispense actually delivered what it was asked to.

Which balance

The driver takes a device type, so it covers more than one Mettler balance. The specifications that apply are those of your fitted model, not a single figure quoted here.

For scale, Mettler Toledo states their analytical balances span:

Capacity	22 g to 520 g
Readability	0.001 mg to 1 mg

Mettler lists density determination, sample preparation, differential weighing, formulation and pipette calibration among the applications for that class. They also offer automatic balances for automated powder and liquid dispensing, and state that extremely small samples can be dispensed at 2 µg readability on their high-precision models.

Confirm your own balance’s capacity and readability before a method depends on a tolerance — a verification range that is tighter than the balance’s readability cannot succeed.

Supported methods

Reading a weight

• Get stable weight — wait for the reading to settle, then return it
• Get instant weight — return the current reading without waiting
• Get stable weight with note / Get instant weight with note — the same, recording a note alongside the reading

Stable versus instant is the choice that matters. A balance settles: a reading taken immediately after labware lands is not the same as one taken once vibration and airflow have subsided. Use stable whenever the number feeds a decision, and instant only when a rough figure now is worth more than an accurate figure shortly.

The with note variants exist so a reading carries context into the record — which step it belonged to, or which plate — rather than being an anonymous number in a table.

Verifying a dispense

• Verify weight increase — confirm the weight went up
• Verify weight increase range — confirm the increase falls within a range

These are the operations that turn a balance into a check rather than a sensor. A liquid handler reports that it dispensed; the balance is what establishes that liquid arrived. The range form is the stronger one — it catches a partial dispense as well as a missing one, which a simple “did it go up” test does not.

Zeroing

• Zero device — zero the balance
• Zero device immediately — zero without waiting

Zero before a weighing sequence, not after a fault has already produced a suspect number.

Integration

Revolution talks to the balance over a serial connection.

Prerequisites

• The balance must be cabled to the Revolution host and its COM port number known before the device is initialised.
• The configured device type must match the balance fitted.
• The balance must be level, settled and draught-shielded as Mettler requires — a balance in a cell with a robot moving next to it is subject to vibration that a bench balance is not.
• Where readings are recorded, the plate database connection must be valid.

Device configuration

Property	Purpose
Com port number	Serial port the balance is connected on
Device Type	Which Mettler balance model this device addresses
Plate DB Connection string	Database the weight records are written to

If you need more of this instrument driven from a schedule, get in touch — the driver is extended on demand.