Study on the Main Factors of Frequency Variation of LC Resonant Prestress Detection Method

Table 4

Ф15.2 mm experimental data of strand length.

l/m	f1 (kHz)	f2 (kHz)	f3 (kHz)	f4 (kHz)	SD	RE (%)	f (kHz)
6.0	103.907	103.909	103.900	103.912	0.0051	0.0115	103.907
6.5	103.183	103.183	103.213	103.225	0.0214	0.0407	103.201
7.0	102.522	102.536	102.538	102.540	0.0082	0.0176	102.534
7.5	101.394	101.395	101.372	101.379	0.0113	0.0227	101.385
8.0	100.745	100.734	100.753	100.748	0.0080	0.0189	100.745
10.0	98.675	98.641	98.652	98.648	0.0147	0.0345	98.654
10.5	97.485	97.462	97.502	97.479	0.0165	0.0410	97.482
11.0	97.287	97.293	97.285	97.283	0.0043	0.0103	97.287
11.5	96.640	96.643	96.642	96.635	0.0036	0.0083	96.640
12.0	95.778	95.784	95.776	95.774	0.0043	0.0104	95.778
12.5	95.482	95.446	95.447	95.485	0.0214	0.0409	95.465
14.0	94.153	94.139	94.162	94.158	0.0100	0.0244	94.153
14.5	93.705	93.698	93.695	93.714	0.0084	0.0203	93.703
15.0	93.138	93.164	93.127	93.123	0.0185	0.0440	93.138
15.5	92.490	92.476	92.512	92.470	0.0187	0.0454	92.487
16.0	92.211	92.202	92.200	92.223	0.0105	0.0249	92.209