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Dr. Pepper

Checking alarm activation temeperatures

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Does anyone know if AABB and CAP are OK with letting your fridge or freezer, if so equipped, electronically test high and low activation temps, rather than doing the old put the probes in a bucket and slowly add cold or warm water method? One would think that if your digital readout is calibrated as accurate, this should suffice, and certainly be easier. This has come up because we are the proud owners of a new Helmer platelet incubator (and thus losing our distinction of being the only BB in the western hemisphere to lack one) where the old method is not practical because the thermocouple is fixed to the wall.

 

The service manual offers two methods of checking: electronically (the box warms or cools the probe), or manually with a 16x100 tube that they tell you fill with hot or cold water and slip up over the probe. (There is a bracket to guide the tube that prevents you from using any other larger container to do so.) In both cases the temperature change was rapid enough to change the digital temp in increments of 0.4o or so and it was hard to see the exact temperature that the alarms were activated. I have the high and low set for 20.5 and 23.5. I think I might try starting with water in the safe zone and add ice water or hot water drop by drop to get a more gradual change and find exactly where they go off. Or just be satisfied as long as they go off above 20.0 and below 24.0. What do you folks do?

 

Thanks - Phil

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Phil - I think it depends on whether or not the electronic test actually raises/lowers the probe temp or just increments the thermometer until the alarm sounds.  I do my Helmer ref 4x/yr - twice electronically and twice the old fashioned way.  My Helmer Plt box and freezer I do the old fashioned way.

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I validated the electronic probe activation to ensure that it works properly. For the platelet incubator, we do check with warm and cool water as recommended by Helmer. The trick is to use water temp that is just outside that range so you get the gradual increase and decrease needed to be able to pinpoint when it alarms. There is also a setting for the threshold alarm that you may have to adjust to get the testing to work (for example if it is set not to alarm until the temp is above 24 for 5 minutes, you'll have to adjust that so that the alarm activates immediately). The manual shows you how to adjust that.

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Thank you Dave. Unfortunately, my fridge and freezer just increment the temp.

 

Thank you Terri, that is what I was going to try. I have the alarms set to sound immediately.

 

And the good Lord giveth, the good Lord taketh away - our FFP freezer died last night, although a valiant attempt at resuscitation and/or resurrection will be made today.

Edited by Dr. Pepper

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Godspeed Dr. Pepper.

 

Do you have an electronic continuous temperature monitoring system or device specific alarms only?

Edited by goodchild

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 This has come up because we are the proud owners of a new Helmer platelet incubator (and thus losing our distinction of being the only BB in the western hemisphere to lack one) where the old method is not practical because the thermocouple is fixed to the wall.

 

 Don't feel too bad. We still have an incubator that is 14+ years old. The chart is a little dicey, but the rest is still functional. And we did get to replace our freezer - just - before it took the big nose-dive.

 

I do an electronic check three times a year but do it the old fashioned way the fourth quarter. Haven't had any issues with inspectors so far.

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Godspeed Dr. Pepper.

 

Do you have an electronic continuous temperature monitoring system or device specific alarms only?

Sorry about the delay in response. Continuous (unlike me).

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