However, if you are looking for a "paper" or guide related to loop checks and commissioning, you likely mean :
Does the device give a different reading if the pressure is rising versus falling? iec 612982
Choose Vendor B. Why? Because you know exactly how the instrument will behave in your plant where summer temperatures hit 45°C. Vendor A's vague claim is unverifiable. However, if you are looking for a "paper"