Liquid nitrogen tank monitoring
Liquid nitrogen sits at around -196 degrees. That is far beyond what a standard temperature sensor can measure, and far below the level the samples can tolerate rising to.
How do you monitor a liquid nitrogen tank?
With a Pt100 sensor specified to -200 degrees, placed in the vapour phase above the liquid. The temperature there rises as the nitrogen level falls, which makes it the earliest indication that the tank needs filling.
A standard digital temperature sensor typically only goes down to around -40 degrees. It will show something, but not something correct, and it will not warn you in time.
Limits are set according to your own SOPs and to how quickly your tanks actually warm up between fills.
The tank runs dry quietly
A nitrogen tank does not fail. It evaporates. That happens all the time, and it is meant to.
The problem arises when evaporation is faster than expected, because the lid did not seal properly, the tank's vacuum has deteriorated, or a fill was skipped one week. The level falls, the vapour phase gets warmer, and the samples at the top are the first to feel it.
With a sensor in the vapour phase, the rise is seen in good time, and there is time to top up instead of moving the contents in a hurry.
What we monitor on the tank
Temperature in the vapour phase
Pt100 to -200 degrees. A rise here is the earliest indication of a falling level.
The tank's own alarm outputs
Level and vacuum alarms are read via dry contact or 4-20 mA and sit in the same dashboard.
Filling system
Automatic filling is monitored, so a failed fill raises an alarm instead of going unnoticed.
Oxygen level in the room
Evaporated nitrogen displaces oxygen. An oxygen meter with an analogue output can be read into the same system.
Escalation
Call, text message and email to the person on call, then on to the next, until someone acknowledges.
Cryo freezers at -150
Mechanical cryo freezers in the same range are covered by the same Pt100 sensor.
OCEAView from DICKSON, set up and looked after by us
The hardware is DICKSON's. The software is DICKSON's. Everything between the equipment and your day-to-day work is ours. And once the system is complete, it is yours. You buy it, you own it, and no leasing agreement decides when you can switch, expand or stop. We handle the maintenance, so it keeps running.
OCEAView
The whole setup on one screen. Watch mode gives a combined status overview of the equipment you have access to, with up to 100 units per page, and each graph can be zoomed down to the individual minute. Plan View also places the points on your own floor plan, so the person on call can see which room it concerns.
Audit trail that cannot be altered
Every measurement, alarm and acknowledgement with timestamp and user. That is what an auditor asks for.
Report in one click
Choose a period and pull the report as PDF or CSV. Ready before anyone asks.
Cloud or your own servers
On-premises runs at your site with LDAP, and you control updates yourselves, so the qualification holds.
DICKSON
The manufacturer
Builds data loggers, sensors and OCEAView. French and American production, its own accredited calibration laboratories and CE, FCC and IC approved equipment.
Djurhuus IT
Distributor since 2018
We advise on placement, design the setup, install, set up alarms and on-call rotas, train your staff on the system and manage calibration afterwards.
You
Owner of the system
The system is yours. You set limits, response times and requirements according to your own SOPs. We supply the system and the documentation, handle the validation, on our own or in close collaboration with you, and maintain it afterwards.
Frequently asked questions
Do you measure the nitrogen level directly?
We measure the temperature in the vapour phase, which rises as the level falls. If the tank has a level transmitter with an analogue output or an alarm output, it can be read into the same system and shown alongside the temperature.
Why not use a standard sensor?
Because it is not specified for the range. A standard digital sensor typically goes down to around -40 degrees, and below that it reads incorrectly without it being visible in the figure.
Where in the tank should the sensor go?
In the vapour phase above the liquid, at the height where the samples are most exposed. We agree the exact placement when we see the tank.
Can we monitor the oxygen level in the room?
Yes, if you have an oxygen meter with an analogue output. Universal Smart-Sensor reads 4-20 mA, 0-5 V and 0-10 V, so the meter sits in the same dashboard as everything else.
What if the power goes?
The tank is passive and is not affected, but the data logger keeps running on battery, so measurements continue. A dry contact on the emergency power also raises an alarm when the system switches over.
How often does the sensor need calibrating?
You define the interval yourselves based on your SOPs, typically every 12 months. The system notifies you when a sensor's calibration is about to expire, and you choose the notice period. The certificate is retrieved directly from the sensor.
De bruger os allerede
Kom hurtigt i kontakt med den rette specialist.
Vi hjælper med alt fra nye monitoreringsløsninger til kalibrering, validering og teknisk support.
Generelle henvendelser
Nye projekter
IT & teknik
Administration
Besøg os
Måløv Byvej 229
2760 Måløv
Ring til os
+45 72 22 02 05
Man-fre, 08-16
Fortæl os, hvad du har brug for.
Vil du se, hvordan det ser ud hos jer?
Book en gennemgang. Vi kommer forbi, ser på udstyr og lokaler og rådgiver om, hvor følerne skal sidde. Derefter får du et skræddersyet forslag. Uden forpligtelser.
Book en gennemgang