4 wire Kelvin temperature sensor PCB Identification/Modification

[Kashif khan]

So i have a job from a client and down below is all the information i got from the client to get started with, He has only two pictures of the PCB which i am attaching.
Any idea what 4-wire test equipment PCB is this? How to go around this problem. Any lead is appreciated.


""""I have a 4-wire thermometer PCB board consisting of a 0.5mA current source and a discrete ADC, using a 400-ohm reference resistor. I need help identifying which resistors to change to increase the current to 1mA and adjust the transconductance accordingly.

Circuit Details:

- The PCB has one reference resistor (MREF) and two measuring resistors (RX1, RX2).
- It operates as a 4-wire system with periodically reversed source currents to compensate for EMFs.
- The resistor under test is selected and switched by three DG612DY switches.
- Measurements start with the unknown resistor RX1, using a positive current (IP) followed by an equal negative current (IN).
- Voltage drops (UX) from these currents are fed into a voltage-to-current (U/I) converter.
- The output current from the converter is connected to a 24-bit resolution current ADC, utilizing a combination of dual slope and charge balance principles for enhanced linearity.
- Transconductance changes in the U/I converter were made to accommodate different currents.
- Measurement currents are selectable between 0.5mA and 1.0mA by switching current sensing resistors.

Requirements:

- Identify which resistors (value and location) need to be changed to increase the current to 1mA.
- Determine which resistors need to be adjusted to change the transconductance for the increased current.
- Specify the necessary resistor if a 100-ohm reference resistor is used"""""