Delta control engineering corporation manufactures digital watt meters,. It has now introduced compact 31/2 digits wattmeters in 92 mm x 46 mm cut-out. These are three terminals wattmeters, suitable for very wide range of pf applications from ±0.2 to unity. The available ranges, without the use of cts, are 20.00 w; 200.0 w and 2000 w. With the use of external cts, the range can be extended suitably. Model 1wt-5a with the ratings of 440 v/5 a/200 w is suitable for three-phase three-wire applications, in which two of these instruments are used. These wattmeters are of high stability type, low insertion loss and are of class: 0.5 accuracy.
