Is there an effective method for testing the functionality of an OEM oil sending unit when not on the car?

I've located a seller that has a black, OEM 6462137 with a good date for my '70 442. The seller has no car to test the unit, but performed a multimeter test on the unit and states it shows as working. There is no oil leaking from around the base of the unit. I did not ask but considering the exterior condition I believe it has been on a shelf for a while--not on an engine.

Considering this unit is quite pricey, is an old electrical part, and I want the part to install on my car, is there a better test, short of installing on an engine to determine functionality, or is the multimeter test effective?

Thanks for your response.

 

Unless you can apply variable pressure, any testing with a meter is just continuity. It won't tell you if the unit actually works when pressure is applied or if it is even close to accurate.

 

From my understanding Redline Gauge Works in California has a service in which they can test and calibrate a rally pack oil pressure gauge to a sending unit. You'd need to ship both components. I've never used this service, but it's an option if you have time and money.

 

A tee fitting on any running engine and an ohmmeter will do the same thing. Use a mechanical gauge as a pressure reference. Three data points should be sufficient as the potentiometer should be linear.