Experimental Investigation on the Influence of Ambient Temperature on the Test Accuracy for the Differential Pressure Hydrostatic Levelling System

Table 4

The influence of ambient temperature on the measurement accuracy of the HLS.

ID	Test platform	Pipe material	Dtest (m)	TA (°C)	TA rate (°C/min)	Test purpose
C1	Single HLS	PU plastic pipe	—	−10⟶30⟶−10	0.05	The effect of temperature rising/falling rate on the HSL test error
C2					0.1
C3					0.2
C4					0.02
C5	Single HLS	PU plastic pipe	—	−10⟶30	0.05	The effect of pipe material on the single HSL test error
C6		204 stainless steel pipe
C7		Polypropylene pipe
C8	Double HLS	PTFE pipe	0.5	−10⟶30	0.05	The effect of pipe material on the double HSL test error
C9		Polypropylene pipe
C10		PU plastic pipe
C11	Double HLS	PTFE pipe	1	−10⟶30	0.05	The effect of measuring distance on the single HSL test error
C12			5
C13			10