"DynoCal" is, in some respects, like an electric car. It is comprised of an AC motor with two wheels, one attached to each end of the motor shaft. It literally drives on the dynamometer rolls under its own power. DynoCal, the computer, and batteries (see below) may be housed in a trailer to allow it to be moved from site to site.

DynoCal follows preset drive traces and makes a number of measurements that allow it to determine how well the dynamometer is performing. For example, it can tell how accurately the dynamometer is simulating the commanded road load and inertia, and how quickly the dynamometer responds to torque and speed changes of the tester. The determination of simulation accuracy is based on sensors entirely independent from those that the dynamometer uses in its own control.

Real Time developed "DynoCal" to meet the needs of the State of California's smog-test program, which required certain passenger cars and trucks to be periodically tested on chassis dynamometers. Because the dynamometers are located in various parts of the state and are made by several different manufacturers, DynoCal had to be portable and adaptable.

The instrument delivered to the State of California has a 67 hp AC motor and regenerative vector drive (see Technical specifications). When 3-phase power is available, it can be operated directly from the line. If not, it can be operated from a set of lead-acid batteries which are recharged from 115 VAC single-phase power. The batteries are also charged whenever the tester is braking the dynamometer rolls (much like an electric car).

The software provides color graphical displays, generates comprehensive reports, automated test functions, and integrated data acquisition.

What can DynoCal do?