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Symptom: Glove Box uses a lot of gas

Possible Causes A: If there has been any condensation in the glove box it is possible the sensor has been temporarily compromised and giving the controller erroneous readings forcing it to purge gas unnecessarily.  Typically this type of gas consumption is dramatic emptying a tank of gas overnight.

Solution:  Remove the Sensor from the Glove Box and Controller and allow it to dry for a 24-36 hour period of time, to speed the process along it can be placed in a dry incubator (not an oven or above 70° C).

Possible Causes B: If this is more of a jump in the typical gas consumption of the glove box over previously expected amounts and there has been no change to the protocols or amount of use, then the prime suspect is a leak in the unit typically around the seal and door area primarily the airlock door.

Solution:  See the section below to confirm a leak into the system closing off the gas at the cylinders so that O₂, N₂ can not be purged into the system.  Then note the glove box O₂ levels and compare the leak levels over a 12-18 hour period of time.  Leak rates greater than .3% indicate a significant leak into the system.  Consult the detecting leaks section below for details on finding glove box leaks.  If there is no noticeable “leak” then the Controller and Sensor are most likely the issue and will have to be sent back for repair/recalibration.

Symptom: Erratic O₂ Readings

Possible Cause: Moisture on the sensor or Defective Sensor/Controller

Solution:  Remove the Sensor from the Glove Box and Controller and allow it to dry for a 24-36 hour period of time, to speed the process along it can be placed in a dry incubator (not an oven or above 70° C).  Once dried reinsert the sensor and observe the readings, if still erratic or unstable contact COY for return of the unit for repair.

Symptom: Glove Box O₂ Readings rise when purging the airlock

Possible Cause: Leak in the seal between the airlock door and the glove box.

Solution: Inspect and clean seal paying particular attention to the connection of the seal to the frame of the airlock door.

Symptom: Constant "clicking" of the Controller

Possible Cause:  The metallic “click” you hear on occasion is the controller’s solenoid valves opening to allow gas to flow into the system.  If this is frequent then it is the first sign that something is wrong with the system.  Possible problems are a leak in the glove box, or improper plumbing of the gas lines, or to high of a flow rate on the controller (either O₂ or the optional CO₂ Controllers) causing the controller to overshoot the desired set point and compensate by turning on the other gas line/solenoid.

Solution: Observe the Flow Meters on the front of the controller(s) and the set-point carefully, if the controller’s display overshoots the desired set-point this is the cause of excess gas consumption and constant “clicking” simply reduce the flow rates until you eliminate the overshoot.  If the there is no overshoot then check the plumbing with the instruction manual to ensure this has been done properly, if this is an established unit that no one has changed the plumbing on you can skip to the next solution checking for leaks.  Prior to checking for leaks you will want to confirm that this is the true nature of the problem by using the following steps listed below in Confirming a Leak.  If there is no leak then contact COY for a return of the Controller and Sensor.

Confirming a Leak in the System:

1. Note the O₂ Levels
2. Close off all Gas to the system at the cyclinders
3. Wait minimum of 12 hours and note the O₂ levels again and Compare
   

NOTE:  It is important to not access the glove box by any means during this period.
If the change in O₂ levels is less than .3% there is no leak in the system as this is seen as an acceptable diffusing rate.  If there is a change greater than .3% this is a leak and not diffusion and proceed to the Finding a Leak Section listed below. 

Finding a Leak in the System:

Leak Check for Polycarbonate based Chambers

1. Place a rag soaked in alcohol inside the glove box.  The Leak Detector will only pick up hydrocarbons and thus the reasoning for this step.
2. Make sure Arm Ports are securely in place
3. Turn on your leak detector and let run for 5 minutes on high. This will allow the instrument to warm-up and be more accurate.
4. Fill the Pressure Relief Valve with water.  You will need the positive pressure to detect most leaks.
5. Using N₂, back fill the chamber until the water starts to bubble from the excess pressure.
6. After your leak detector is warmed up, set the instrument to a slow steady beep. Slowly move around the chamber looking for possible leaks. Pay close attention to the doors, and the diaphragm top.

Patching a Leak in an Acrylic Chamber:

1. When you have pinpointed the leak you will now need to patch the crack or hole.
2. Depending on how big the crack or hole in the chamber is, you can use glue or silicone. If there is an actual hole in the chamber it is better to use silicone and let dry for 2 hours before rechecking for leaks. However, if there is only a slight crack in the chamber it is recommended to apply glue along the crack first and then apply a small amount of silicone over the glue. Big long cracks in a chamber must be stopped. The best way to accomplish this is to drill a small hole at both ends of the crack. Then fill the drill hole with silicone.

Note: After patching a leak with silicone do not to use the chamber for at least 24 hours to allow the silicone to set.

Note: The glue is extremely adhesive to polymer as soon as it makes contact with the polymer it will start to set. It behaves like water do not spill on your chamber. Be very careful when applying.  Ask Coy for syringe and applicator tip when applying glue.

Items needed when checking and repairing leaks:

1. Gas Leak detector
2. Alcohol
3. Cloth Rag
4. Silicone
5. COY Acrylic Glue with Syringe and Applicator tip