| 'unknown' | '?' | 
                        
                            | 'Voltage' | 'V' | 
                        
                            | 'Current' | 'A' | 
                        
                            | 'Time' | 'Secs' | 
                        
                            | 'Frequency' | 'Hertz' | 
                        
                            | 'Resistance' | 'Ohm' | 
                        
                            | 'Conductance' | 'Sie' | 
                        
                            | 'Capacitance' | 'F' | 
                        
                            | 'Inductance' | 'H' | 
                        
                            | 'Energy' | 'J' | 
                        
                            | 'Power' | 'W' | 
                        
                            | 'Charge' | 'C' | 
                        
                            | 'Flux' | 'Vs' | 
                        
                            | 'Volt???MATH???^2???MATH???' | 'V???MATH???^2???MATH???' | 
                        
                            | 'Volt???MATH???^2???MATH???/Hz' | 'V???MATH???^2???MATH???/Hz' | 
                        
                            | 'Volt/rtHz' | 'V/rtHz' | 
                        
                            | 'Amp???MATH???^2???MATH???' | 'A???MATH???^2???MATH???' | 
                        
                            | 'Amp???MATH???^2???MATH???/Hz' | 'A???MATH???^2???MATH???/Hz' | 
                        
                            | 'Amp/rtHz' | 'A/rtHz' | 
                        
                            | " (means dimensionless - see notes) |  |