53
Basic programming setup
f.
Select Take First Sample Immediately or After First Interval?
Note: When the program is started, the first sample is taken immediately upon pressing the start
button or after the first interval has elapsed.
g.
Press
ACCEPT
to continue to Sample Distribution.
Flow proportional constant time, variable volume sampling (CTVV)
A level-velocity sensor input must be logged and electrically connected for the CTVV
feature to work correctly.
CTVV samples are taken at user-specified constant (fixed) intervals. However the actual
volume of each sampling is based on the known average flow rate of the site, the actual
metered flow rate for each specific interval, the total sample volume desired, the
user-specified collection period, and the specified Sampling Interval. Depending on the
flow volumes of a stream and various intervals within the Collection Period, the volume of
individual sampling can vary. Also, the total sample collected during the entire period can
carry slightly above or below the Total Volume Desired. For these reasons, the
manufacturer advises using a sampling container that has a larger volume than the Total
Volume Desired value.
•
Sample Distribution menus are not available when CTVV is selected.
•
A level-velocity sensor input must be logged and electrically connected for the CTVV
feature to correctly work.
•
The Flow Pacing Mode menu within the Flow Proportional menus sequence will not
remember the previous setting. Whenever you re-enter this menu, it will revert to the
CVVT default. When re-entering this menu, press
CHANGE CHOICE
to select the
sampling method, CVVT or CTVV.
Example:
This is an example of how the instrument determines sample volume, based on user
inputs and actual metered flow volume.
The user entered values are the following:
•
Average flow rate (historical, site specific): 150 gph
•
Sampling interval: 2 minutes
•
Total sample volume desired: 1500 mL
•
Collection sampling period: 30 minutes
11:00 AM 21 - APR - 01
SAMPLE COLLECTION
ACCEPT
TIMED OVER-RIDE:
00:00 (hrs:min)
CANCEL
CLEAR
ENTRY
ENTER: 000:01 — 999:00 (hrs:min)
11:00 AM 21 - APR - 01
SAMPLE COLLECTION
ACCEPT
CHANGE
CHOICE
TAKE FIRST SAMPLE:
_______________
CANCEL
CHOICES: IMMEDIATE, AFTER 1
st
SAMPLE
Goodnal STP ST041 Pre Treatment (Sigma 900 MAX All Weather Refrigerated Sampler) Vendor Manual
Q-Pulse Id VM373
Active 29/10/2013
Page 53 of 122
