1
00:00:10,200 --> 00:00:12,900
Hi, I’m Andrew Cardamone.

2
00:00:12,900 --> 00:00:14,300
Today I’m going to talk to you about

3
00:00:14,300 --> 00:00:16,633
how to adjust user factors
for alloy analysis

4
00:00:16,633 --> 00:00:19,300
using your Vanta XRF analyzer.

5
00:00:19,300 --> 00:00:22,533
User factors allow us to adjust
the factory default calibration

6
00:00:22,533 --> 00:00:25,400
to account for any matrix
or material effects.

7
00:00:25,400 --> 00:00:28,066
This can be done using certified
reference materials,

8
00:00:28,066 --> 00:00:29,800
your own internal standards,

9
00:00:29,800 --> 00:00:32,100
or samples that have
been assayed in a lab.

10
00:00:32,100 --> 00:00:35,200
Sometimes, for alloys, the
factory default calibration

11
00:00:35,200 --> 00:00:37,566
has to be adjusted
for a particular element.

12
00:00:37,566 --> 00:00:40,566
We recommend using at least
three standards to do this.

13
00:00:40,566 --> 00:00:42,366
However the more standards you use,

14
00:00:42,366 --> 00:00:45,033
the more robust
the calibration will be.

15
00:00:45,033 --> 00:00:50,066
The first step in this process
is to analyze your samples.

16
00:00:50,066 --> 00:00:53,300
The sample test time can be the
same as your standard test,

17
00:00:53,300 --> 00:00:55,066
or to minimize variation,

18
00:00:55,066 --> 00:00:59,933
2 to 3 times longer than your
standard sample time.

19
00:00:59,933 --> 00:01:03,766
For this sample the nickel
content is assayed at 65%.

20
00:01:03,766 --> 00:01:07,733
We can see here that we’re
obtaining a value of 76.7%.

21
00:01:07,733 --> 00:01:12,133
I will now export these results
and graph them in an XY plot.

22
00:01:12,133 --> 00:01:14,800
As you can see I’ve done
that here in Excel,

23
00:01:14,800 --> 00:01:17,600
with the Vanta XRF
results on the X axis

24
00:01:17,600 --> 00:01:20,600
and the lab assay values
on the Y axis.

25
00:01:20,600 --> 00:01:23,633
I have also enabled the display
equation feature on the graph.

26
00:01:23,633 --> 00:01:27,833
This allows us to obtain the slope
and the Y intercept of the graph.

27
00:01:27,833 --> 00:01:32,033
I will then use these values to create
a user factor model on the Vanta.

28
00:01:32,033 --> 00:01:36,233
To do that I will open
the user factor icon,

29
00:01:36,233 --> 00:01:38,566
hit the plus button
to create a new model,

30
00:01:38,566 --> 00:01:44,233
and give it a name,
in this case NI for nickel.

31
00:01:44,233 --> 00:01:48,166
I will then import the factors
we determined on the graph.

32
00:01:48,166 --> 00:01:54,033
. So the factor will be the slope,
which is point 650.

33
00:01:54,033 --> 00:02:01,466
And the offset will be the
Y intercept, which is point 459.

34
00:02:01,466 --> 00:02:10,533
I will then re-test the sample.

35
00:02:10,533 --> 00:02:14,300
Recall that the assay value for
this sample was 65% nickel

36
00:02:14,300 --> 00:02:20,800
and that initially we were
measuring it at 76.7% nickel.

37
00:02:20,800 --> 00:02:22,866
You can now see that
we’ve measured the

38
00:02:22,866 --> 00:02:25,566
concentration of nickel at 66.3%,

39
00:02:25,566 --> 00:02:27,733
which is a much closer assay match.

40
00:02:27,733 --> 00:02:30,566
Although it is uncommon,
matrix effects

41
00:02:30,566 --> 00:02:34,600
can have different impacts at low
and high elemental concentrations.

42
00:02:34,600 --> 00:02:38,600
Because of this, two different user
factor models can be established.

43
00:02:38,600 --> 00:02:40,500
You can then swap between
these user factor models

44
00:02:40,500 --> 00:02:42,333
during your testing to allow for

45
00:02:42,333 --> 00:02:45,733
accurate concentrations
over a wide range.

46
00:02:45,733 --> 00:02:47,433
I hope that showing you
how to integrate

47
00:02:47,433 --> 00:02:50,100
user factors into your
alloy testing has been useful.

48
00:02:50,100 --> 00:02:51,666
Thank you for watching today.