The U6-Pro and T7-Pro provide some of the best performance around from a 24-bit ADC, and they do about 22 bits effective or 20 bits error-free. If you look at a device called "24-bit" just because it has a converter that returns 24-bits of data per sample, you will find that it typically provides 20 bits effective or 18 bits error-free (like the UE9-Pro). What we like to do, is provide actual measured data that tells you the resolution of a device including typical inherent noise. It is hard to simply state "the resolution" of a given device. The simple fact that a converter returns 16-bits says little about the quality of those bits. When an ADC chip returns 16 bits, it is probably better than a 12-bit converter, but not always. When you see analog input DAQ devices from various manufacturers called 12-bit, 16-bit, or 24-bit, it generally just means they have an ADC (analog to digital converter) that returns that many bits. What does it mean to say a device is 12-bit, 16-bit, or 24-bit? This gives a voltage resolution of 20/4096 or 0.00488 volts per bit (4.88 mV/bit). In the case of the LabJack U12, a single-ended analog input has a voltage range of -10 volts to +10 volts (20 volt total span) and returns a 12-bit value. Low voltages give a 0 and high voltages give a 1. It might occur to you at this point that a digital input could be thought of as a 1-bit analog to digital converter. A 16-bit digital value can represent 65536 (2 16) different numbers. A 12-bit digital value can represent 4096 (2 12) different numbers. A 3-bit digital value can represent 8 (2 3) different numbers. So in this example, the 2-bit digital value can represent 4 different numbers, and the voltage input range of 0 to 10 volts is divided into 4 pieces giving a voltage resolution of 2.5 volts per bit.
This device will give digital values as follows: Now, say you have a device which converts an analog voltage between 0 and 10 volts into a 2-bit digital value for storage in a computer. If you are storing a digital 2-bit number you can store 4 different values: 00, 01, 10, or 11.
#Logger pro 3.12 series#
A computer is a digital machine and thus stores a number as a series of ones and zeroes. Resolution in this context refers to the conversion of an analog voltage to a digital value in a computer (and vice versa).
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