The Innovative Design of Deep In Situ Pressure Retained Coring Based on Magnetic Field Trigger Controller

Table 2

Maximum magnetic force of the valve cover when the valve seat consists of four identical shape tile magnets in six schemes.

Distance (mm)	Maximum magnetic force (N)
	Scheme 4	Scheme 5	Scheme 6	Scheme 7	Scheme 8	Scheme 9
1	265.098	344.533	169.530	171.384	190.576	236.777
5	64.168	111.624	52.093	53.455	67.263	97.531
10	16.374	37.288	16.272	17.915	27.857	46.035
15	6.575	14.886	6.697	7.862	13.646	24.548
20	3.369	6.221	3.027	3.873	7.242	13.931
25	2.174	2.749	1.534	2.120	4.042	8.028
30	1.552	1.247	0.843	1.238	2.287	4.806
35	1.151	0.586	0.512	0.771	1.350	2.915