Re: [AMMRL] Varian 400MR Liquid Helium Fill Timing

From: Eugenio Alvarado via groups.io <ealva=umich.edu_at_groups.io>
Date: Mon, 19 May 2025 12:46:49 -0400

Stephen,

The digital readout value refers to the "Probe reading (mm)" in the
chart. You don't have to wait until it gets to 100 mm.  In fact, you
could order a 60L tank and time your refill so you can use all of it. 
That would be at around 230 mm (50L transferred and 10L loss).  If you
order a 100 L tank, and want to use most of it, that should be at a
probe reading of about 40 mm, which to me is a little too close to the
minimum level.  Keep in mind that the probe reading is never 100%
accurate.

Eugenio

Eugenio Alvarado, Ph.D. NMR Facility Director Chemistry Department, room
3500. University of Michigan 930 N. University Ave., Ann Arbor, MI
48109-1055. Voice: (734)-764-9924

On 5/19/25 11:26 AM, Stephen Nolte via groups.io wrote:
>
> Hello,
>
> I’ve been following the notes of our previous technician to perform
> the liquid helium fill when our probe reading is around 100. I also
> found the attached helium probe calibration chart, and I’m wondering
> if I’m performing the helium fill prematurely. Does the digital
> readout value on the probe refer to the “Probe reading (mm)” column or
> the “He level in can (mm)” value? Should I be waiting a little longer
> before the fill?
>
> Thank you!
> _______________________________
>
> Stephen Nolte | Chemistry Technician
> Millersville University
> 717-871-7413
>


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#2353): https://urldefense.com/v3/__https://ammrl.groups=
.io/g/main/message/2353__;!!PvDODwlR4mBZyAb0!Wrgjg0WPE_DBL_pXyeWB5AMhFmDX3w=
qxycGLD5Qz_XOxBIPsJdrkkrjDXrKL0w2dR8y6yh55l0azHQ_EOw5WDBS1GY0$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/113194325=
/7559972__;!!PvDODwlR4mBZyAb0!Wrgjg0WPE_DBL_pXyeWB5AMhFmDX3wqxycGLD5Qz_XOxB=
IPsJdrkkrjDXrKL0w2dR8y6yh55l0azHQ_EOw5W3ZjRupI$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-




Received on Mon May 19 2025 - 10:08:15 MST

This archive was generated by hypermail 2.4.0 : Sun Jun 01 2025 - 15:26:23 MST