I am using Belsorp mini BET instrument. During the measurement, in the desorption stage, I face a message saying "V5 (F) needle valve is too tight" and the analysis interrupts.
I changed the V5 valve rang on the instrument to loosen the valve, but it did not help. Even I replaced the gas cylinder pressure regulator and the filter on measuring cells.
What would be the reason for such an error and how it can be resolved?
Thanks in advance.