4167P Portable Transformer Ratiometer.

The Transformer Ratiometer Type 4167P 
measures the transformation ratio of large 
transformers and also gives an indication of any 
small phase difference between the high 
voltage and low voltage windings (e.g. primary and secondary). 

The ratio and phase difference or ratio and energizing voltage are displayed on two large digital LCD displays with optional back light for use in poor light conditions. 

In use the High Voltage winding of the transformer under test is connected to the “H.V. Winding” terminals of the instrument and is energized by the internal power oscillator at a nominal 60 Volts AC./50Hz. The low voltage winding (Step down) is connected to the “L.V. Winding” terminals. 

The display of ratio and phase is then entirely automatic. 

Measurement technique 

The measurement technique is to measure the H.V. and L.V. voltages during several parts of the cycle to obtain in-phase and quadrature values from which the ratio and phase difference are calculated. 

The input circuits are isolated by transformers, therefore the instrument should not be damaged by the very high voltages possible if the connections from the transformer being measured are accidentally reversed. 
The measurement circuits are further protected by front panel fuses with internal surge absorbers.

Power Requirement 

The 4167P is fitted with rechargeable batteries and has an internal charger. The instrument can be used connected to a mains power supply or will operate from the internal batteries for a period of up to 8 hours from a full charge.