All component storage units are equipped with an an alarm system that is monitored 24 hours/day, with alarm check (for both low and high settings) ......

Does this mean we need to check the low temp for freezers too????? I don't know how to achieve this 

An excellent question. In theory, there is no such thing as "too cold" for a freezer, so the low temp. alarm setting seems to be pointless. However, if such a unit does activate a low temp. alarm, it may indicate that the unit is malfunctioning in some way. It might just give you time to intervene before the unit goes "bang". I hope I've sufficiently emphasized the low probabilities of the above happening.

Our facility still checks the low alarm points for our walk-in freezers (-20 C). Luckily, we have access to liquid nitrogen (LN2) which is very convenient and quick. In the past, we've very awkwardly used a sludge of alcohol and dry-ice to get a very low temperature (-60 C), but this doesn't help with ultra-colds (-80 C).

For physical science reasons, we are unable to activate the low alarm on our liquid nitrogen tank !!!! We actually had an inspector challenge us on this issue a number of years ago.

Interesting, I don't remember ever seeing a freezer that even had a low temp alarm let alone a way to check it!  I think we just figured that part didn't pertain to freezers.

Most freezers equipped with automatic alarm test has low and high.

And yes if the manufacture instruction says to do hign and low, we must do high and low alarm check.

19 hours ago, Eagle Eye said:

Most freezers equipped with automatic alarm test has low and high.

And yes if the manufacture instruction says to do hign and low, we must do high and low alarm check.

This is news to me but then things do change with time.  So my questions are, first, are the alarms set at the factory or by the facility?  Second, at what temp is the lower alarm set?

On 12/2/2017 at 2:38 PM, Eagle Eye said:

Most freezers equipped with automatic alarm test has low and high.

And yes if the manufacture instruction says to do hign and low, we must do high and low alarm check.

This is our interpretation of CAP question that you need to follow manuf. requirement. 

We have a helmer freezer and the suggestions in the manual for maintenance is to test high and low temperature alarms quarterly. Our low limit is -35 Celsius and our high is -20 Celsius. The alarm limits can be set at the facility.

Edited December 8, 20177 yr by NicolePCanada

Okay... my question is this: In order to do a low alarm check on your freezer, how would you go about getting the temp low enough to do the testing? Like most BB refrigerators, for example, ours has the wands that we can "trick" the fridge into triggering the low and high alarms. How would you trick the fridge? Currently, our plasma fridge is at -60. How could you fake the temp lower than that or am I thinking about this wrong? We've never been cited here for alarms on the freezer as long as I've been a tech.

Have never done low freezer temps.  Never been cited.  Never cited anyone either.

I'm not sure how you could trigger a low alarm in an ultralow freezer when it runs at about -80C. I don't even try.

Edited December 11, 20177 yr by AMcCord

On 12/10/2017 at 10:56 AM, EAB81 said:

Okay... my question is this: In order to do a low alarm check on your freezer, how would you go about getting the temp low enough to do the testing? Like most BB refrigerators, for example, ours has the wands that we can "trick" the fridge into triggering the low and high alarms. How would you trick the fridge? Currently, our plasma fridge is at -60. How could you fake the temp lower than that or am I thinking about this wrong? We've never been cited here for alarms on the freezer as long as I've been a tech.

 

6 hours ago, AMcCord said:

I'm not sure how you could trigger a low alarm in an ultralow freezer when it runs at about -80C. I don't even try.

How do you calibrate or verify calibration of your freezer temperature probes  ?

The Helmer i-series freezers come with an automatic alarm check for high and low settings.  The freezer itself when the alarm check button is pressed warms and cools the probe to a temperature below or above the setting to get the alarm to go off.  This does not however show a spike on the chart recorder because only the temperature probe is adjusted (not the chart recorder probe).  Manufacturer's instructions state to test the high and low alarm quarterly.

19 hours ago, exlimey said:

 

How do you calibrate or verify calibration of your freezer temperature probes  ?

I have a stick thermometer with a current calibration certificate in the ultra-low freezer. When maintenance is done, the temp of the thermometer is documented along with the temp on the freezer LED display and the chart temp.

You can indeed test the circuitry of the freezer by pressing a button for an alarm check (love that feature!), but how do you perform a physical test of the low alarm to make sure that your circuitry is functioning correctly?

20 hours ago, AMcCord said:

I have a stick thermometer with a current calibration certificate in the ultra-low freezer. When maintenance is done, the temp of the thermometer is documented along with the temp on the freezer LED display and the chart temp.

You can indeed test the circuitry of the freezer by pressing a button for an alarm check (love that feature!), but how do you perform a physical test of the low alarm to make sure that your circuitry is functioning correctly?

I was wondering if the probe was able to be moved, but probably not. I'm sure the manufacturers don't want the end users monkeying with their delicate electronics. If the probe could be moved, it might be possible to angle it into liquid nitrogen (LN2) - that would set off the low/cold alarm ! That's what we do in my facility, but our probes are accessible/flexible enough that we can move them around fairly easily.

May I assume that you're only doing a one-point calibration/certification of the freezer probes ?

1 hour ago, exlimey said:

I was wondering if the probe was able to be moved, but probably not. I'm sure the manufacturers don't want the end users monkeying with their delicate electronics. If the probe could be moved, it might be possible to angle it into liquid nitrogen (LN2) - that would set off the low/cold alarm ! That's what we do in my facility, but our probes are accessible/flexible enough that we can move them around fairly easily.

May I assume that you're only doing a one-point calibration/certification of the freezer probes ?

You are correct about assuming that the probes are not accessible - in fact they kind of bury them in the freezer wall on the unit we use. No liquid nitrogen in the lab anyway and I'm not aware of anyone in the hospital keeping a supply of it on hand. And Yes - one point calibration. We are strictly a transfusion service with storage for tendons and bone. We haven't had any interest from inspectors about freezer alarm issues - hoping it stays that way.