Does this watt-minute meter have anything to do with
your previous thread from two years ago, involving sixty-four silicone insulated heaters mounted on a slowly rotating (~3 revolutions per hour) wheel?
I am curious about the purpose of the rotating heater wheel and how, with just two wires for power, you determine which heater will be energized as the wheel rotates? You mentioned slip rings, but these usually apply power continuously to objects on a rotating shaft. How do you select one heater to power out of sixty-four? Did you ever get the RFID tags to work with the spiral heating elements embedded in the silicone rubber heaters without burning out the tags?
It sounds to me like you are sorely lacking in instrumentation to perform electrical/electronic experimental setups. Spend a few bux so you will learn how to do it right. A decent digital multimeter, a digital RCL meter, and an inexpensive digital storage oscilloscope would be a good start. You can add more expensive stuff later if needed/desired/wanted. I have been using the Asian test equipment just mentioned for many years without problems, but you need to be careful of which vendor you select. Google will be your best friend there, but you have to do the research and make the final choice. Ask for suggestions here and in other online forums.
@Bluejets suggestion to run a number of turns of wire carrying the heater current through the toroid core of the current transformer is not a "trick" but a simple way to increase sensitivity of the current measuring part of your metering device. It may increase it too much, causing the current measurement to be "off scale" at higher inrush (cold) heater currents. This will be especially true during the inrush current that occurs when the heater elements are first energized, leading to inaccurate power measurements.
If it were my project, I would "roll my own" power meter, designing the "front end" electronics for the worst-case initial conditions of excitation voltage to the heater and maximum transient inrush current expected, then sampling and digitizing these two analog signals at a fast rate while multiplying the digitized results in real time. The product will be in watts of course, so you need to accumulate the products over a period of time to yield watt-minutes or watt-seconds or whatever energy units are appropriate to whatever it is you are trying to DO. BTW, just WTF are you trying to DO?
