You have PPT which is Parts Per Thousand, not trillion. Multiply your number by 1000 to turn your PPT to PPM (Parts Per Million). So, a reading of 0.95PPT would be the same as 950PPM.

You need to check the manual for your pen to find out what solution it requires to calibrate. It may need EC or PPT, and who knows what concentration. If it doesn't say in the manual, look up the product on the manufacturer's website and it should have it there.