TR: Turns ratio
Ensures that the number of turns on each winding and the winding polarity meet specification.
Unit of measurement, Decimal Ratio. 1:100k to 100k:1 with a signal level from 1mV to 5V @ 20Hz to 3MHz
Turns ratio is measured to establish that the number of turns on primary and secondary windings are correct and therefore the required secondary voltages are achieved when the transformer is in use. It is important to remember that the various transformer losses shown figure 1 will result in a voltage ratio that does not correspond exactly with the ratio of physical turns present on the windings. The AT series testers include the ability to calculate turns from the ratio of inductance (TRL) which overcomes errors attributable to core loss and leakage inductance. This and other turn ratio considerations are described in a separate technical note VPN: 104-113.
Figure 8 Example test entry screen for Turns Ratio using the Editor program.