This is the relay board for a PIC microcontroller driven resistor decade box. PCB low resistance:3 1K R22, R23, R241 1K8 R263 1R R1, R2, R31 1R8 R51 2K2 R251 2R2 R41 3K3 R281 3R3 R71 4K7 R271 4R7 R63 10R R8, R9, R101 18R R121 22R R111 33R R141 47R R133 100R R15, R16, R171 180R R191 220R R181 330R R211 470R R202 100nF C1, C22 74HCT595 IC1, IC32 ULN2803 IC2, IC416 TQ2-24V K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12, K13, K14, K15, K16PCB high resistance:3 10K R1, R2, R31 18K R51 22K R41 33K R71 47K R63 100K R8, R9, R101 180K R121 220K R111 330K R141 470K R133 1M R15, R16, R171 1M8 R191 2M2 R181 3M3 R211 4M7 R202 100nF C1, C22 74HCT595 IC1, IC32 ULN2803 IC2, IC412 TQ2-24V K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12More information can be found here: https://en.elektronicastynus.be/category/projects/measuring-equipment/resistor-decade-box/
