Flow not reaching desired rate

[Don_Hilton]

I've not used this model inlet - so check the manual. The k-factor, as I understand it is the instrument's measurement of the column - which would be a pressure drop measurement. (Thus be sure everything on the inlet is leak tight - or the k-value calculation will be wrong.) Pressure Drop is a function of column length and diameter. The instrument has to be given one of the two values somehow. Check the manual for a discussion on changing columns.

[lusi]

Hi Don. As far as I could tell everything on the inlet was leak tight since it was fully functionally the Friday it was turned off. We have done several leak checks on the system, but found nothing. The only place a leak can really be is inside the system and at this point in time I am not experienced or authorised to do that sort of leak checking. However, the suppliers will be here late next week. T

[CE Instruments]

The Thermo GC system runs a K factor determination and a leak check. You can check additionally by checking the calculated K factor is correct by looking at the K factor sheet provided with the GC that provides the theoretical value based on column dimensions. The most common cause of an "internal" leak with these systems is the solvent trap prior to the DPFC. Just lift the covers off the top of the GC and the trap should be visible. I have seen these just come apart causing a leak, easily fixed. Beware over tightening of the septa , this causes septa to be punched into the injector by the autosampler needle giving high bleed. It should be possible to achieve a seal by just finger tightening when cold (SSL injector)

[lusi]

Thanks CE Instruments. I will definitely check the area you indicated. I did remove the cover and check all the parts that were visible before but found nothing. As I mentioned before the system was unable to perform the column evaluation using that injector. However, it worked perfectly with the other injector.

[lusi]

The service technicians had to change the board and the problem was then resolved. So no leaks no blockages - an electronic problem.

[Rachel S]

I also have a Thermo Trace GC Ultra. There is no option to enter the column configuration. I have not had the problem you have so I have not tried to do the checks you are doing. My GC is on a GC/MS system.

[lusi]

Hello Rachel S. My system does not allow you to manually enter the column configuration either. The column evaluation adjusts the system accordingly. Anyway, the system is up and running find also.

Now we have a DSQII connected to it.