Thanks Elden.
19.5 mV with a 3 ohm internal resistance yields 6.3 mA FS, which is close to my 5 mA measured on two different meters. Being 85 years old, I find the difference understandable.
The markings on the Thermocouple do indeed indicate a max of 0.75 A:
I have a problem with the chart. With a 3 ohm internal resistance, here's the voltage across the meter with the indicated current values:
With a meter reading of 1, the voltage across the meter is 18X the FS value of 19.5 mV.
If 19.5 mV is FS, and that's with 0.75 A through the meter, then the internal resistance is 0.026 ohms, which is in the ballpark of my value of
0.033 ohms.
73 Mark K3MSB