Today’s analytical lab balance is a product of over 60 years of continuous innovation from a handful of equipment manufacturers around the globe. Each improvement has aimed to increase the analytical lab balance’s precision, accuracy or reliability for researchers. The origins of the modern analytical lab balance date back to the short-beam analytical assay balance produced by Sartorius in the early 1900’s (pictured below). This article will look at the major technological breakthroughs—from the first single-pan analytical balance manufactured in 1945 to that which more closely resembles what’s in your lab today.
The invention of the single-pan analytical balance by Mettler Toledo company founder Erhard Mettler. The company was established as Einzelfirma E. Mettler, in Switzerland. With the introduction of its scale, the company broke the less accurate two-pan weighing mold, using Mettler’s so-called “substitution principal” to achieve more accurate measurements. Large-scale production of the unit began in 1946.
The first nanogram balance sets the world record for the most precise weighing. This balance, manufactured by Sartorius, was used to weigh the moon rocks that astronaut Neil Armstrong brought back to Earth from his expedition.
Mettler debuted its PT1200 scale, the industry’s first fully electronic precision balance. With a capacity of 0 to 1,200 grams, the PT1200 had sensitivity to 0.01 grams. The new balance proved immediately successful upon its official 1974 launch.
Sartorius debuts the world’s first explosion-protected version of an electronic precision balance.
Since the beginning, manufacturing state-of-the-art force restoration balances required the controlled assembly of numerous parts, dissimilar metals and fasteners carefully torqued and aligned to tight specifications. The resulting hardware was subject to small but unpredictable changes due to ambient temperature changes and aging.
Shimadzu’s R&D engineers clearly addressed this problem and envisioned a solution in their 1989 patent for a single piece force-restoration balance mechanism. Their solution would only be fully realized when manufacturing technology advanced to include computer numeric control (CNC) milling and electric discharge machining (EDM) machines capable of cutting a block of metal alloy to a single piece that replaced as many as 70 individual parts. This is the technology now present in Shimadzu UniBloc and Mettler Monobloc components, which deliver stability of calibration against temperature changes and time, and enable quick response by reduced mass and movement. Computer-controlled cutting eliminates many hand assembly steps, assures manufacturing quality control and ultimately reduces cost.
Mettler Toledo introduces the first electronic microbalance with a 51 million point resolution.
With the introduction of the revolutionary MonoBloc weighing cell, Mettler Toledo set another milestone. More compact, robust and durable than its predecessors, it has become the reliable and precise “heart” of many of their balances.
Sartorius introduces the world’s first ultra-microbalance with a weighing capacity that features a resolution of 21 million digits and an accuracy of 0.1 μg.
The first monolithic weigh cell technology is presented by Sartorius. The monolithic weigh cell replaces a complicated weighing system made up of up to 150 different parts. This new mechatronic system is the basis for many successive generations of balances and scales.
Most balance users must eventually record weight or computed values generated by their balances. Often, additional calculations are performed, such as combining weighing data with other instrument analysis, to compute sample values.
Shimadzu’s Windows Direct communication function makes this easy. Winner of the most outstanding new product award at the International Society of Weighing and Measurement (ISWM) exhibition in 2000, Windows Direct allows the user to leverage the capabilities of any Windows-based software. Once configured, the displayed weight is transmitted directly to the PC just as if it were entered via the keyboard. No additional software is needed to interface with spreadsheet, database, word processing or laboratory software. This function eliminates data input errors, offers extensive flexibility for application development, and simplifies system validation and compliance. Windows Direct also works together with other balance functions to automate weighing data collection.
Mettler Toledo’s introduced many innovations with their new XP analytical series analytical balance. Adding a color touch screen, Bluetooth connectivity and the peerless gridpan technology that gave a major improvement in stability and accuracy.
Sartorius releases the Cubis analytical lab balance whose many firsts include: The first balance in its class with automatic motorized leveling at the touch of a key; the first top-loading analytical balance with a motorized draft shield; and the first lab balance with Q-Pan off-center load compensation that adjusts accordingly when a sample is off-centered on the pan. All this means reliable and repeatable results in a larger working area.
With 61 million digit resolution, the Mettler Toledo XP6U sets a new benchmark in measurement performance. The XP ultra-micro balances are designed to boost weighing efficiency, reliability and support network compatibility.