nagel temp gauge
 

anybody use one. I need to know what sensor is used.

Re: nagel temp gauge
 

No, but pictures and more details would be helpful. A google search turns up a variety of temp gauges under nagel.

Re: nagel temp gauge
 

There are various types of temperature gauges, those with expanding gas sensor, those with a thermo-couple sensor, & those with a transistor temperature sensor. In my opinion, the least accurate and least reliable type temperature gauge is gas type.

> The gas temperature sensor uses ether to expand a coiled tube in the gauge. The coiled tube is known as a Bourdon Tube. The failure mode is leakage of the gas. This type of gauge is era correct for the Model A.
> The thermo-couple sensor has 2 different metal wires welded together in the sensor. As the temperature increases, the differential metals produce a voltage that is indicated by a gauge with a D'Arsonval electromagnetic movement. This type of gauge is also Model A era correct.

> The digital gauge uses a transistor as a temperature sensor. As the temperature of the transistor changes, the current output of the transistor changes & is displayed with a gauge containing a digital ammeter. This type of gauge is correct for post 1950 vehicles, but usable in a Model A.
The Rex-A-Co Gauge is a gas type & the APCO Gauge is a thermo-couple type.

Re: nagel temp gauge
 

Nagel made an electric temperature gauge during the Model A era. It used a resistance type sensor element that was about 500 ohms cold and decreased resistance in about 3 steps. I do have one of the sensors for my gauge and I do think that there is a modern unit that can be used. I will try to dig my unit out of storage and add more information later.

John

Re: nagel temp gauge
 

john i am very interested in the proper sensor for this unit its a strange one. The pattent no. on the meter is no help. An odd thing about the meter is that when i put a 1.5 v battery across it reads in a positive direction regardless of the direction of the battery.

Re: nagel temp gauge
 

there are a couple on ebay but they dont have the bracket to attach to the steering column mine does. the patent data is no help with sendor its a strange one. any info on sendor operation or theory would be nice so i can make one

Re: nagel temp gauge
 

look up patent number 1621396 and see if you can make sense of it

Re: nagel temp gauge
 

I am out of town on a trip. I will post more information when I return home.

John

Re: nagel temp gauge
 

I think i have it figure out. The dial does not show temp just cool normal and hot no temps, the prob is just a two position thermal switch. off no conection=cool. position 1= normal with resistor for half scalel normal. position 2 hot is full 6 v full scale.