kadriver - 20-2-2013 at 09:35
I stumbled across one of these and it was very cheap ($15 USD) so I bought it.
Trouble is, I have no clue what it is or how to operate it.
Can someone give me some assitance?
It came with a probe that appears to be some sort of fuse holder.
An operators guide or maintenance manual in PDF file format would be great.
Thanks!
kadriver
MikeSomething - 21-2-2013 at 11:41
I called Cole-Palmer and spoke to a tech support person. Manuals aren't available. It was introduced in 1978, and discontinued in the early 1990's.
The good news: this is a device designed to control power to 120vac devices. The probes with which it would work are either a thermocouple switch,
pressure sensor, a flow meter, a proximity sensor, or a 0 - 9999 counter. The tech said the set point was set in/at the detector; the Lab Monitor III
is simply a relay that turns on or off the 120vac outlets on the front panel at the given set point.
This would be useful to control a heating mantle, if you can find the right temperature sensor to feed the Monitor. A regular thermocouple probe won't
work. You'd need a switch that either opens or closes at the set point, rather than an analog sensor.
The probe you have might be a proximity switch, or a flow meter. The flow sensor in this case would simply acknowledge flow via thermal change,
similar to automotive mass airflow sensors, but not tell you necessarily your exact flow rate.
Another idea is for maintaining flow in a gas generator. This could be used to actuate a valve and/or a mechanical stirrer once gas flow has slowed.
It's kind of a rare situation, unless you have a reaction that takes a few days to run.
If you post a pic of the sensor, I can probably tell you what it is, especially if it has a part number on it. I work with a variety of proximity
switches. I can send you one to play with if you want.
You can probably get more info from Cole-Palmer at 1-800-323-4340. Press 3 for tech support. I told them the company name I used to work for, and that
we were upgrading our lab. I said I had one of these devices sitting in a cabinet, and wondered if we needed to replace it in the process of securing
funds for said lab replacement. I got the impression that Cole-Palmer is one of those companies that you don't need to bullshit - they'll help
anybody. Still, it might be helpful to be able to rattle off a university department with which you're familiar, in case they ask for credentials.
kadriver - 25-2-2013 at 15:52
The company responded to my email request and gave me a copy of the manual for this in a PDF.
The probe has two clips (I thought it was for a fuse).
According to the manual, the probe is attached to a thermometer with these clips. Then the probe reads the temp by sensing the position of the mercury
in the thermometer.
When the mercury hits a predetermined point (determined by where it is positioned on the mercury thermometer) a switch it thrown and power is cut off
to the selected outlet on the front of the lab monitor..
As the temp falls the probe senses that the mercury has moved lower and the power is re-established to the outlet.
It can also sense a column of mercury and respond in the same way to changes in pressure (inches of mercury).
Thanks mikesomething for your help.
Kadriver
Organikum - 25-2-2013 at 17:22
Yes these switching thermometers were state of the art for nearly 100 years , I
can still buy them on Ebay fro example. They exist as fixed temperature and as adjustable ones being simple as hell (at least the fixed ones) - the
mercury column raises up to the point two electric contacts are shorted by it. Some even switch serious amounts of power, 220V 3A or more. If you want
some look on german Ebay the fixed ones go for less then 10€ the adjustable ones for about 15€ IIRC. Proximity sensors of the time and probably
fitting to your Palmer are available too, other sensors for sure also. This are the leftovers from the great German Democratic Republic Relieable though outdated hardware. Quality is mostly rather good.
PM me if you need help there.
So thats a power relais basically? Whats the "Cycle" switch for?
Lab Monitor might be a bit euphemistic a naming though....
cheers
/ORG
MikeSomething - 28-2-2013 at 05:33
Your welcome, kadriver! Glad they found a manual for you. ;-)
As I understand the device, when the "Cycle" switch is set to "limit", the output is only toggled once, such as to turn off a heating element once the
desired temp is reached. When set to "Diff" (shirt for 'differential' in this case), the output will toggle on and off within the differential range
of the sensor. It can be used to maintain a temperature range this way.