MTFML Fluid Cell Engage Problem

paul.kirkman posted on Fri, Feb 10 2012 11:19 AM

rated by 0 users

Hi all,

I've recently started work using the MTFML fluid cell on a MultiMode IV system. I'm operating in contact mode, but seem to have big problems engaging the surface. I'm using SNL-10 tips, but the problem doesn't seem to be limited to these tips. Because I haven't been able to engage properly, the cell is also empty of fluid.

I follow the standard procedure for engaging in contact mode, with deflection set point at 0 V, and the deflection at roughly -1.5 V before beginning the engage, but when I begin to engage the deflection decreases, becoming more negative rather than tending to zero. This will start quite slowly, but the deflection will reach -2/3 V pretty quickly, and then rapidly continue decreasing, presumably once in contact with the surface. 

Using exactly the same tips/procedure with a regular MFMA holder I have no problem at all, so I'm certain this is all because of the holder. I've tried positioning the tip differently in the holder, and adding in packing beneath the tip to distance it from the holder, but this seems to make no difference at all. I'm not sure if it's an odd effect of the laser passing through the glass cell, or the actual tip itself.

Has anyone else had experience with this holder, good or bad?

Regards

Paul