Latency or the delay as you mentioned is significantly caused due to the conversion process chain which starts from the sensor to your monitoring system (computer). Fast acquisition devices may reduce latency to great extend, however, the communication channel used, the quality of the cables used/length of the cable, processing power of the computer, background services running in your computer also adds to the latency which makes the entire system sluggish. I would recommend you to check the data flow channel from sensor to computer and also try different cable/computer. I hope I could share some light on the problem. Thanks.

@Ajit Paul Abraham thanks for your answer,

it makes sense that different apparatus show differents data due to the factors that you mentioned, I tought that those factors could affect my data in the order of 1to10ms. I'll test with differents cables and computers.

I am glad I could be of some help. Please let me know if I can help you further. Thanks.