Sartorius microbalances are often overlooked in favor of similar Mettler MX series and Mettler MT series models. But with ME5, Sartorius has introduced a model that is comparable in function and quality to almost any other microbalance on the market.
Microbalances are sometimes sub-categorized as analytical balances but are actually 100 times more sensitive than a standard analytical balance, with analytical models weighing with 0.1mg precision and a microbalance weighing to a millionth of a gram. There are some crossover analytical or “semi-micro” models like the Mettler AX26 and AT20 with sensitivity to 0.002mg to 3g, but the high precision of a microbalance distinguishes these units from the broader category of analytical balances.
First, let’s get technical with some specs. The ME5 has a 5.1g capacity and a readability of 1ug. Repeatability is +/- 1 microgram and linearity is +/- 4 micrograms. The average response time is 2.5 seconds while Sartorius lists the official response time as 10 seconds, still impressive for 1ug model. Like all microbalances this model is sensitive to ambient temperature fluctuations and will potentially drift by up to 1ppm per degree of Celsius change within the 5°C to 40°C recommended operating temperature range, so you should calibrate regularly especially if your lab isn’t strictly temperature controlled. The circular weighing pan has a diameter of 30mm.
The built-in air buoyancy correction program software (called EUREKA) is a nice feature and helps compensate for fluctuations in air density that could normally impact readings at the microgram level. The pre-loaded software also allows for storage of tare-weights, initial sample weights and calculation of the amounts backweighted for up to 50 samples.
We like all the features noted above. The one part of the balance that we haven’t been thrilled with thus far is the draft shield. The motorized shield is a single piece of glass with an anti-static coating. The idea behind this design is to allow users to have an interference-free view of the weighing chamber and platform. While this sounds like a good idea in theory what we’ve found is that in practice the shield tends to have less stability and is more prone to slip off its seating. And because the glass is so thin this can easily lead to a shattered draft shield, which is very costly to replace.
Now, all that being said, we’re still in favor of the idea of a shield with no frame components or other visual impediments, and this feature certainly shouldn’t be a deal-breaker when considering the Sartorius ME5. We’re currently experimenting with creating an impact resistant plastic shield coated with anti-static conductive material to replace the glass shields.
The ME5 can be calibrated using external weights or with the built-in auto-calibration feature called isoCAL. This is a fully automatic calibration and adjustment that ensures consistently high accuracy and is particularly useful in quality management systems. This function can be triggered by a change in temperature or automatically activated at defined intervals or specific times of day and charted through the calibration record memory.
With the price of new microbalances currently weighing in (pun absolutely intended) at over $40,000, the refurbished Sarotrius ME5 microbalance is a cost-effective option with enough features to satisfy almost any lab, including those with ISO or GLP quality management systems.
We have a few used and refurbished microbalance models in stock and available, including the Sartorius ME5. All of our products come with a 90 day warranty. Please call or email us today for more information on this unit. Thanks!
American Instrument Exchange has been a reliable source for used laboratory and scientific equipment for over 50 years, buying and selling equipment since 1969. Our surplus lab equipment is reconditioned for many types of laboratories, including biotech, biomedical, medical research, chemical, pharmaceutical, and university and hospital research laboratories. All lab equipment listed on our website is in stock and ships from our 30,000 square foot warehouse in Massachusetts. Our facilities include a fully equipped shop with highly trained technicians who thoroughly test each instrument before it reaches your laboratory. Please visit our website at https://www.americaninstrument.com/.