Update file ultra-freezers.md

external/lab-equipment/ultra-freezers/ultra-freezers.md

@@ -35,11 +35,11 @@ All the freezers are monitored via a software called Sensor4Lab. To avoid any al
 Please note that there is a 30 minutes delay between the moment that you disable the sensor and the response of the system. This means that you should disable the monitoring 30 min before you start the maintenance.
 
 
-### How to defrost a -80C freezer
+## How to defrost a -80C freezer
 
 This section describes the maintenance steps of the Ultra-Low Temperature Freezers from Sanyo (MDF-U76V-PE, MDF-U76V-P and MDF-U74V).
 
-#### Inner doors defrosting - once a month
+### Inner doors defrosting - once a month
 
 With repeated opening and closing, frost builds on the inner doors of the chamber. Excessive frost can cause some gaps between the cabinet and the magnetic gasket, resulting in poor cooling. 
 
@@ -69,7 +69,7 @@ With repeated opening and closing, frost builds on the inner doors of the chambe
 -	Fill the maintenance form located on the door of the freezer
 
 
-#### Air intake port cleaning - once a month
+### Air intake port cleaning - once a month
 
 When the freezer door is closed, the warm air that entered the chamber cools down rapidly, and contracts causing a negative pressure. 
 This is the reason why it is difficult to open the freezer shortly after it was closed.
@@ -94,7 +94,7 @@ Some -80°C freezers are equipped with an air intake port, which allows to count
 -	Fill the maintenance form located on the door of the freezer
 
 
-#### Condenser filter cleaning - once a month
+### Condenser filter cleaning - once a month
 
 <div align="center">
 <img src="img/img15.png" width="300">
@@ -108,7 +108,7 @@ Some -80°C freezers are equipped with an air intake port, which allows to count
 -	Check that the filter check lamp is off
 -	Fill the maintenance form located on the door of the freezer 
 
-#### Inner chamber defrosting - once a year
+### Inner chamber defrosting - once a year
 
 -   24h before your maintenance, inform the Instrument Care team by sending [a ticket](https://service.uni.lu/sp?id=sc_cat_item&sys_id=6ea39fdbdbec38105c72ef3c0b96196a&sysparm_category=af924f17dbac38105c72ef3c0b96194b) and [disable the Rmoni sensor](#how-to-deactivate-the-alarm-in-Sensor4Lab)
 -	Switch off the freezer (the switch is located at the bottom of the left side of the freezer)