Omega Datalogger and the HotTop

Complete Unit with both probes

In the previous post I had attached the Omega HH506RA to one KTSS-HH probe and mounted that probe in the HotTop. Now I attached the second probe for the drum temperature.

All of this started with a web page by Randy Glass. (page gone now)

Here is the guide that was mode on how to modify the top to install probes. I did not write it. Mods to cover for probes

After attending roasting school I wanted both a bean and drum probe. The probe built into the HotTop is above the bean mass.

Probes Inside the Drum

I purchased an extra HotTop chute cover from a local supplier. It was only $6 Cdn. This gave me the comfort that if I messed up the part I could still roast with my old one. What I was surprised was how hard it was to drill the holes. One warning: BE CAREFUL. The chute cover is made of two pieces of metal, a plastic handle and two screws. You can break the plastic.

As the drum rotates counter clockwsie, the beans pool from 7 to 3 o'clock

I found the easiest way to cut the lower slot was using a Dremel to cut the slot between two holes. One nice thing is the probes do not need to be moved to slide the cover on.

Logger and Probes

In this picture I loaded the roaster but turned it off and removed the front cover. The drum rotates counter clockwise so the beans pool from 7 to 3 o’clock. As the ‘right’ bean probe is lower it site in the bean mass. The drum probe was raised since the first picture.

The next challenge is learning the Omega logger. The instructions are cryptic. You can download them. I have not experimented much with the software yet. I will write a guide to the datalogger next. It is easy to use once you understand it. You could manually save a reading every minute for later reference.

The display is divided into three areas. In the top is Probe 1 for the bean temp, Lower left is the drum temp and in the lower right is the difference between the temperatures. Much of this is configurable.

Other probes could be used by buying Type-K Miniature Connectors such as SHX-K-M

My goal is to connect this to my computer and automatically log the data using the plotting software I wrote earlier. I will post more details later.

Off to have a nice cup of Ethiopian Yirgacheffe.

5 thoughts on “Omega Datalogger and the HotTop”

  1. Hey Rich it looks like your on to something. Question ? Are you using the probes which are connected to the Logger just for bean temp or are they for both temps. The reason ask is that they seem to be close together according to the photos.

  2. Hi Sal. They are close together but in the photo the one on the left is up out of the beans. The drum turns counterclockwise so the beans pile up at say 7 o’clock to 3 o’clock positions.

    I will post a picture with the cover off

  3. Rich. So my question is this: Will the plotter software be written using the JavaBeans API? Great to see your fantastic progress on the temperature logging which will help create some very reproducible roasting profiles. Thank you for posting the details.

  4. The API is a call to the serial port. I have the raw interface specs but I am not a Java person. Wish I was. I think I could have client Java talking to the serial port and feeding the results to the web.

    BTW, I do see the humour. Right now I am thinking of writing something in VB as I used to work in that.

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