You may struggle to get temperature sensor parameters as is usually something propriety but some workshop manuals sometimes give basic test values.
Some times you can get lucky as there are a limited number of sensors to choose from which can withstand the harsh environment of an engine block.
Often a manufacturer will pot a standard sensor in there prob.
So if you remove it and make a measurement of the value in ice water at 0DegC and another in boiling water at 100DegC you can often see which one it is likely to be from widely available sensor data.
Taking a reading at other Temps would be better but may be a little harder without thermomitors in your water.
It may be Nickel or Platinum wire wound with the NTC or PTC coefficient determined by your test.
Even if you cannot pick it from a list you find out enough info to plot where the value likely be at higher temperatures so you can place a variable resistor in place of the sensor and test your relay.
The function and temperature accuracy of the relay is more important at the cold end of the range.
You can calculate your approx maximum on time of your new glow plugs when you get them before installing them.
If you attach a solid power source from your battery to the glow plug, time with a stop watch how many seconds it takes until they just start to glow red and stop.
It would be good to test all your new plugs before installing as often if one is going to fail it is often on first use.
Expect a lot of smoke when they are first energized.
Some times you can get lucky as there are a limited number of sensors to choose from which can withstand the harsh environment of an engine block.
Often a manufacturer will pot a standard sensor in there prob.
So if you remove it and make a measurement of the value in ice water at 0DegC and another in boiling water at 100DegC you can often see which one it is likely to be from widely available sensor data.
Taking a reading at other Temps would be better but may be a little harder without thermomitors in your water.
It may be Nickel or Platinum wire wound with the NTC or PTC coefficient determined by your test.
Even if you cannot pick it from a list you find out enough info to plot where the value likely be at higher temperatures so you can place a variable resistor in place of the sensor and test your relay.
The function and temperature accuracy of the relay is more important at the cold end of the range.
You can calculate your approx maximum on time of your new glow plugs when you get them before installing them.
If you attach a solid power source from your battery to the glow plug, time with a stop watch how many seconds it takes until they just start to glow red and stop.
It would be good to test all your new plugs before installing as often if one is going to fail it is often on first use.
Expect a lot of smoke when they are first energized.