Thermal Vac Gauge Question

[tarheel_tech]

I have recently found a Thermal micron gauge in the back of our shop.I believe it came from a sale we went to a few years ago.Well to start with it would not calibrate,so I went and order a sensor for it (model# 4510) which was what it had with it.Now it will calibrate,but when I hooked it to a vac pump no go.It slowly goes to atmospheric pressure and I have my other 2 YJ micron gauges on the same pump and they are reading the samething. What am I doing wrong?The model# of it is 14500

[snewman24]

If all three micron gauges are reading atmospheric, then either the pump isn't pumping, or you have a big leak. Hook up your low-side compound gauge directly to the pump. It should pull down to 29" almost instantly even with a 36" hose. This is a good "go - no go" test. If the pump is OK, then you must have a BIG leak if the micron gauges don't pull down at all.

[tarheel_tech]

If all three micron gauges are reading atmospheric, then either the pump isn't pumping, or you have a big leak. Hook up your low-side compound gauge directly to the pump. It should pull down to 29" almost instantly even with a 36" hose. This is a good "go - no go" test. If the pump is OK, then you must have a BIG leak if the micron gauges don't pull down at all.

I am sorry,I must not have explained it clear.

The 2 YJ micron gauges are reading that it is under a vaccum,while the Thermal one is reading at atmospheric.I have all of them hooked to a titan manifold,and the 3/8" is hooked to the pump.And the gauges are showing a vac,so I know the pump is working.Any thoughts?

[beachtech]

there should be a number on the sensor you have to program, if it is a different calibration number than the original sensor

[snewman24]

I am sorry,I must not have explained it clear.

The 2 YJ micron gauges are reading that it is under a vaccum,while the Thermal one is reading at atmospheric.I have all of them hooked to a titan manifold,and the 3/8" is hooked to the pump.And the gauges are showing a vac,so I know the pump is working.Any thoughts?

If the sensor is new and assumed to be good, then it must be in the meter circuitry somewhere. I don't see the 14500 calibration instructions listed on Thermal Engineering's site but I'll bet the other models are similar. It will probably help you to troubleshoot the problem by looking at the other calibration instructions. You'll need the right resistor and an accurate milliameter. That's how I calibrated my model 4501.

http://www.thermalengineeringcompany...cfm?p=28&pp=15

[tarheel_tech]

It will calibrate but won't work in read mode.Thats for the link snew

[snewman24]

It will calibrate but won't work in read mode.Thats for the link snew

The "calibration" you're talking about is just adjusting the calibration knob to match the calibaration value on the sensor (i.e. 31.5 or whatever) in calibration mode. If you'll take time to read the factory calibration instructions, you'll see that it's a more in depth calibration procedure in READ mode. I don't think your problem is actually a calibration (accuracy) problem since you don't get any vacuum reading at all. I think you have a bad component or a bad connection, but the calibration process will give you a feel for how the micron gauge works.
I think if you take it apart and "play" with it you will find what's wrong (just don't "ohm it" directly across the meter movement or you might burn it out).. It's a fairly simple design. Probably just a series circuit with a battery, meter movement, sensor (variable resistor) and trim pot (adjustable resistor). As the sensor senses a lower vacuum, it lowers it's resistance and sends more current to the meter movement and deflects it farther to the right.

http://www.thermalengineeringcompany...01,%204575.pdf

[ctrlaltdel]

Try checking the washers.

[tarheel_tech]

Try checking the washers.

Where are they at?

[ctrlaltdel]

Where are they at?

Should be able to find them near the end of the tube. Or use the traditional test for leakages.

Now can someone make me a pro member? ^^

[itsiceman]

I am sorry,I must not have explained it clear.

The 2 YJ micron gauges are reading that it is under a vaccum,while the Thermal one is reading at atmospheric.I have all of them hooked to a titan manifold,and the 3/8" is hooked to the pump.And the gauges are showing a vac,so I know the pump is working.Any thoughts?

The Thermal is sensitive to cold temps.

They recommend room temp for it to work.

Was it in a cool place?

Now can someone make me a pro member? ^^

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