521A and 521C Electronic Counter
| First Catalog | <year> |
|---|---|
| Last Catalog | <year> |
| Count Rate | 120kHz |
The 521-series counter was the first portable and moderately-priced model. Compared to the 521A, the 521C adds an additional display digit, and adds a 10-second gate time. The 521C also includes the 521A-59B crystal-controlled time base as a standard feature.
