Microbalance & Ultra Micro Balances

A micro balance or ultra-microbalance can deliver the highest precision of all lab balances. This high sensitivity in micro balance design allows for the weighing of sample quantities with weight as low as 30 μg.  

Microbalances offer a capacity of up to 10.1 g with readability down to 1 µg (0.000001g).
Ultra microbalances offer an incredible full resolution of 61 million digits, with a capacity of 6.1 g and 0.1 µg readability (0.0000001g).

METTLER TOLEDO’s portfolio includes a micro-analytical balance. It has a readability like a micro balance, 1 µg, andd the shape of an analytical balance, with an outer and inner weighing chamber.The XPE micro-analytical balances deliver the highest capacity, coupled with the lowest possible minimum weight . This enables dosing of very small amounts directly into a "large" tare containers.

A micro balance consists of two components - one containing the electronics and the other, the precise mechanical measuring cell. This separation eliminates the effects of temperature and the influence it has on the performance of your micro balance scale.

METTLER TOLEDO XPR Micro and Ultra-Microbalances are equipped with an Active Temperature Control system (ATC™). This increases the weighing stability and enables an outstanding level of performance and accuracy.

Microbalances and ultra microbalances are frequently used in product testing and quality assurance labs, as well as chemistry labs and mining to measure small amounts of powders and minerals. Medical device research might also employ a micro balance to check uniformity in critical components.

Micro balance applications include: particulate matter (filter) weighing, pipette calibration, analysis of pesticides, and stent weighing. Ultra micro balance applications include: particulate matter (filter) weighing, ashing or incineration, drying, measurement of coatings, and checking spillage quantities.

To find the appropriate METTLER TOLEDO micro balance for your needs, first define the smallest amount you need to weigh and how accurately you need to weigh it (i.e. acceptable tolerance) to determine the precise micro balance you require.

Every measurement on any balance is subject to uncertainty - understanding this uncertainty is key to ensuring accurate results and the avoidance of errors. When weighing small samples on a microbalance, uncertainty is almost entirely due to repeatability (i.e. at the low end of the weighing range of a specific balance). It is not the readability that determines the accuracy of a weighing instrument, but rather its repeatability, or depending on it, its minimum weight capability.

Ask your METTLER TOLEDO consultant about GWP^® Recommendation which helps you select the right weighing instrument for your own individual requirements.

A micro balance is an extremely sensitive instrument – the slightest disturbance caused by environmental influences or user interaction can significantly affect measurement stability. All possible sources of vibrations should be avoided when using a micro balance. Microbalances are highly susceptible to air currents, dust, and fluctuations in temperature, and should only be used where ambient temperature and humidity are maintained at a stable level – away from vents, windows, and doors.

Ideally the balance should be set-up on a solid workbench - preferably a dedicated weighing table that can remain optimised for micro balance use, free from draughts or high traffic.

When a micro balance is first connected to the power supply or switched on, a minimum warm-up time of 6 hours is recommended for ambient temperature adjustment.

When using the micro balance, be sure to minimize convection flows inside the weighing chamber, which can negatively impact results. Only handle samples with tweezers, and allow acclimatisation to room temperature. When placing the sample onto the micro balance, the door should be opened to a minimum degree, for as short a time as possible.

Follow METTLER TOLEDO’s dedicated guide to weighing, 10 Steps to Successful Micro-Weighingand get further tips on how to deal with challenges when weighing with microbalances, including determining proper balance location and calibration.

Always wear gloves while working with microbalances – fingerprints and oil from hands affect results. To start a weighing operation, open the door and place a container on the pan using tweezers. Close the door and allow the value to stabilize. Tare the micro balance. To avoid spills in the balance remove the container or weighing boat, dose the sample outside the weighing chamber, and place the sample on the weighing pan. Close the door and wait for stability. Record the net weight or repeat the procedure until desired weight is reached. A micro balance is highly sensitive to movement - do not touch the bench while waiting for the balance to stabilize. Clean the balance, tools and workspace after each use.

The draft shield of METTLER TOLEDO’s XPR micro balance provides easy 360° access to the weighing pan and all-round visibility. There are no edges or corners where sample material could become trapped, and all parts can be removed, cleaned, and replaced in a few simple steps.

The accuracy of a weighing device is determined by correct micro balance calibration - performed by a qualified service provider only. The calibration certificate proves a micro balance is working correctly, user routine balance testing detects potential issues in performance within a calibration interval.

Automated adjustment functions with internal test weights, such as FACT or proFACT, ensure that the balance maintains accuracy, even during fluctuations in ambient temperature.

METTLER TOLEDO has developed a globally applicable scientific standard for the secure selection, calibration, and operation of weighing equipment, known as GWP^®, or Good Weighing Practice™, and Balance and Scale Calibration and Adjustment – Clarification of Terms