Having attended metrology conferences, namely the Measurement Science Conference and the NCSLI Symposium and having been around calibration people for 20 years, I can tell you that when it comes to metrology, new test equipment is considered unproven. A piece of equipment with, say, 10 years of history has a known and often predictable performance between calibrations. To some, that gives measurement confidence. But new equipment means a lack of proven performance history, no matter how well it's characterized by the manufacturer. When a new calibrator comes along, its designers know that customers will thoroughly evaluate it.
When Fluke Calibration released its 5730A multifunction calibrator on September 18, it was a big deal for the company. Why? Because the calibration community needs proof that a new piece of equipment will perform within specifications. I recently spoke with Jeff Gust, chief metrologist at Fluke Calibration, about what Fluke did to provide confidence in this new calibrator.
The Fluke 5730A multifunction calibrator replaces the 5700A.
The 5730A is the first new calibrator in its class since Fluke introduced the 5700A in 1988. I've seen the 5700A in many a calibration lab. In 1997 I wrote about going to a calibration lab where a 5700A was used to calibrate an HP34401A.
"The 5730A combines tried-and-true technologies with technologies that weren't available 25 years ago," said Gust. He also noted that, when it comes to equipment with a long life, the components used then are often no longer available. That often forces test-equipment makers to redesign their products, usually resulting in a new model with more features than the old one. Even though a new model can take advantage of new technologies, people get used to using equipment a certain way and they don’t want to change too much, even if that change is for the better.
Many calibration labs use the Fluke 5700A to calibrate multimeters and other equipment.
Even if components are still available, they may be available only in lead-free versions. That's an issue for sensitive calibration equipment, because lead-free components need higher soldering temperatures than their leaded cousins. That puts additional stress on component values during manufacturing. Equipment designers must take that into account.
Given the lack of components used in the 5700A, Fluke engineers needed to design the new calibrator. They took advantage of technologies such as capacitive touch screens when designing the 5730A. Other improvements included lighted rings around the terminals needed for a particular connection. That, according to Gust, "lit up" a few eyes of 5700A users. It cuts down on connection mistakes because technicians can better see where to make connections.
Because calibrators may stay in service for decades, and because people want to minimize operational learning time, the 5730A keeps some operations identical to its predecessors. For example, Fluke engineers kept the front-panel wheel for changing calibrator output settings. People do appreciate the touch screen, which has fewer menus and more information available on the screen. For example, it displays how long ago the calibrator was calibrated.
Fluke engineers did, though, leave many 5700A features intact, such as the ability to calculate error percent. With that feature, a technical dials in an output voltage, current, or resistance on the calibrator until the instrument under test reads the designed value. From that, the calibrator knows the percent error.
Do you use a 5700A (or 5720A) calibrator in your lab? What do you calibrate with it?