Maker Pro
Maker Pro

freezer detection

mike1978

Jul 29, 2023
4
Joined
Jul 29, 2023
Messages
4
Looking for something that would cause an alarm if a person stays in a freezer for over 5 minutes. All I need is a relay closure or open. Thanks
 

mike1978

Jul 29, 2023
4
Joined
Jul 29, 2023
Messages
4
Looking for something that would cause an alarm if a person stays in a freezer for over 5 minutes. All I need is a relay closure or open. Thanks
Thanks for the quick reply My customer wants a way to determine whenever a person enters this freezer that goes down to -20 and does not exit in 5 minutes an alarm would be triggered and others notified in the plant. Thanks for your suggestions
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
I have a suggestion go with that next time full description I left my crystal ball at home anything else?
Would you like a DIY or you want to purchase it off the shelf you want it module so you can just plug and play what power source in your plant
Where would you like it located outside the freezer or inside the freezer think about it!
Throw everything that you got at me this way I can give you an in-depth recommendation.
Basically I'm doing your job for you but that's okay we don't want anybody to get hurt
 

mike1978

Jul 29, 2023
4
Joined
Jul 29, 2023
Messages
4
Thanks Delta Prime
Have a walk in freezer, goes down to -20 employees go in daily Management fears one will fall down or pass out and go undiscovered for hours. They wanted a way that a person could enter the freezer and a timer would start for 5 minutes and if they have not left a horn on the outside of the freezer would sound. I can install 2 card readers and mark them READER IN and READER out and require them to scan their card when entering and leaving, each of these card swipes would produce a form C relay trip from open to close or close to open. They are asking for 5 people tracking abilities, I could put 5 reader ins and 5 reader outs and require them to place their badge in a pouch below the reader in so if others come in they know which reader in to use and when the person leaves they know which reader out to use. The last caveat is that during the 5 minutes they are in there they want a motion to alert the same horn that someone is in there and not moving around.

I can tie the horn into a security system that will alert other peoples cell phones in the plant to the emergency
Thanks for your help.
 

mike1978

Jul 29, 2023
4
Joined
Jul 29, 2023
Messages
4
I have a suggestion go with that next time full description I left my crystal ball at home anything else?
Would you like a DIY or you want to purchase it off the shelf you want it module so you can just plug and play what power source in your plant
Where would you like it located outside the freezer or inside the freezer think about it!
Throw everything that you got at me this way I can give you an in-depth recommendation.
Basically I'm doing your job for you but that's okay we don't want anybody to get hurt
power source in plant is 220 or 110 and they can install that wherever we want it.
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
Because this is a person's life we're talking about I would stay away from Arduino and raspberry pi.There I said it!!
I may have a partial solution .The motion detection inside the freezer would be a excellent redundant failsafe.Sounds to me like RFID checkpoint they call it a night watchman for security guards old school. They come in various configurations but the easiest and reliable would be a ring that one would wear. Very similar to your capabilities.
The RFID reader would be placed outside the freezer.
Before entering the person would place the ring in proximity of the reader and the countdown will begin the countdown will begin.
The person wearing the ring must come out of the freezer and place the ring again in close proximity to the RFID tag disabling the alarm and resetting the clock or timer. If not the alarm would be triggered. Personal computer software is involved and configurable time and date stamps and even an individual ID so multiple persons can have rings. it's configurable with computer software would be passive so temperature inside would not affect a ring. The software should & does include time and date stamps, & the person's ID who's wearing the ring .The logistics you would have to sort out concerning the personnel and compatibility of the software but it's very user friendly. As far as motion detection is concerned inside the freezer.Following link is only an example .
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
I think I might have a more robust solution but stand by I'm pretty sure others may have far more insight than I. And thank you for the information you have provided. I'll be back
 

Bluejets

Oct 5, 2014
6,918
Joined
Oct 5, 2014
Messages
6,918
The system falls on it's face as it relies on user input (which is proven as unreliable)
Even monitoring door operations would be unsuccessful as one entry could follow another, hense any exit is unrecorded so-to-speak.
Locking or unlocking any access door with a card reader or any other means would be highly illegal.

One could turn off the fan coil fans during occupancy which will cause the interior temp to rise and then create an audible and visible alarm.
Problem is, any system is fraught with failure to begin with as it is not fail-safe in itself.
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
@Bluejets thank you for the correction. I misspoke. I should not have used failsafe.

May I ask what are the individuals going be doing inside the freezer, the activity involved?
In the freezer itself who is the manufacturer.
I can point you in the right direction where to start doing some research.
If you combine a gyroscope and an accelerometer you get an IMU Inertial Measurement Unit they come in wearables and be placed inside your parka before you go into the minus 20° C freezer. Connectivity will depend on the the materials used for the freezer.
 
Last edited:

Bluejets

Oct 5, 2014
6,918
Joined
Oct 5, 2014
Messages
6,918
May I ask what are the individuals going be doing inside the freezer
Op obviously referring to commercial cold room arrangement .
Access is for just that, access to the contents.

The whole idea is beyond electronics monitoring as they (electronics) themselves create an additional situation.
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
The whole idea is beyond electronics monitoring as they (electronics) themselves create an additional situation
There must be safety inspections for the company to staying compliance mandated by a regulatory commission and along with proper training for employees concerning safety protocols.
The added safety implementation of electronic detection shows diligence on behalf of the company for the well-being of their employees.
 

Bluejets

Oct 5, 2014
6,918
Joined
Oct 5, 2014
Messages
6,918
The added safety implementation of electronic detection shows diligence on behalf of the company for the well-being of their employees.
Not if it is not an approved so-called "safety implementation".
Personell would under your explanation become complacent and reliant on an electronic device which (as yet...possibly never will) has no compliance.
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
Personell would under your explanation become complacent and reliant on an electronic device which (as yet...possibly never will) has no compliance
Not changing the rules the laws.
They are already being ahered too. No compliance needed!
Your concerns have merit!
Attention to all employees before entering the walk-in freezer the distinctive blue color Parka jackets in various sizes located just outside the freezer door must be worn.
The IMU will be placed inside the parka or even a couple of them oblivious to the employees they will never know. What they will know is that card or a ring
(perhaps a card because the ring can slip off the finger)will monitor
the time allotted , 5 minutes, while inside and must be place near the card reader outside the walk-in freezer to deactivate the alarm that will sound in the entire facility. No complacency they would be oblivious to the IMU located in the parka.
 

Delta Prime

Jul 29, 2020
1,956
Joined
Jul 29, 2020
Messages
1,956
I think you need to install a PIR sensor inside the freezer.
Those units are proven , manufactured specifically for walk-in commercial freezers ,operate below minus 40° C
Trapped: Deaths inside freezers can be prevented, but how?. AP News. Accessed April 2018.
What is Dry Ice?. New York State Department of Health. Accessed April 2018.
Masked man robs Chipotle restaurant in Orange at gunpoint, locks employees in freezer. Joshua Sudock. The Orange County Register. Accessed April 2018.
Occupational Safety and Health Standards. Occupational Safety and Health Administration. Accessed April 2018
 
Top