FYI: These tubes are measured in autobias mode according the manufacturer data sheet.More information you find at the end of this describtion

BTW: You know the difference between tube test and measurement? Most testers merely perform tests, and these involve an inaccuracy of up to 30%. Only a few testing devices truly deserve the label "measuring instruments."

2 x tubes   ECC83 12AX7 Mullard 

Valvo printed >>  genuine Mullard UK tubes Blackburn

Matched pair
ribbed plates
I63 B7K2 coded



Emission much better than 100% 
Measured in autobias mode
Gm/µhmos 1860+1730 and 1900 + 1750 (new = 1600mA >1300....1950< )  
Anode current Ia:  1,3 + 1,28mA und 1,28 + 1,26mA (100% = 1,2mA ±0,15mA)

Please do not confuse "S / gm" with "Ia". 
Only the value s / gm says something about the emission and thus the life time
Measuring device used: RoeTestV11.

Measurement mode: Autobias as specified by the manufacturer.
In autobias mode the tube is measured with a constant anode current. This corresponds to the application in the device.
Note: Most tubes offered on ebay are tested with a fixed grid bias voltage. Such a measurement contains a general system error. The desired result in the application is therefore purely random.