F-1
Appendix F. Response Code 4
Scenarios
A vacuum time out error (response code 4) is returned to the user as part of the
sampler status values when the necessary volume of water does not enter the
metering chamber and complete the circuit between the volume control tube
and liquid sensing/conductivity rod. In other words, there is not enough water
to complete the sample as the sampler is configured (volume depends on the
setting of the volume control tube and conductivity rods).
As discussed in earlier sections, it is important to have at least half an inch
height separation between the bottom of the volume control tube and the
bottom of the conductivity rod. This offset is necessary because of the
turbulent flow conditions as the sample enters the metering chamber. If the
water supply’s level varies and the water supply could dry up, we highly
recommend using a water detection probe to check if enough water is available
for the sample. Also, it may be necessary to increase the height difference
between the bottoms of the two tubes in the metering chamber to more than an
inch. The increased offset is necessary because the water is shot into the
chamber under pressure as the sampler tries to vacuum up enough water to
complete the circuit causing the water surface to jump.
Also, it is possible to overfill a bottle when a vacuum time out error occurs.
See the scenario below.
Example 1: PVS5120D with 24 bottles and 25 ft of intake hose. It keeps 150
mL for each sample (bottom of the volume control tube is set at 150 mL within
the metering chamber). Three samples are stored in each sample bottle for a
total volume of 450 mL. The conductivity rod is set at 500 mL.
In this example, the sampler purges for 15 s. It then starts vacuuming the
sample into the hose and metering chamber until it touches the conductivity rod
(at the 500 mL line). Next the sampler purges the volume from 500 mL down
to 150 mL, drops the 150 mL into the sample bottle and then purges the rest of
the hose for 15 s.
The following status values are returned to the user in sampler attempt 1.
TABLE F-1. Status Value
Status Value
Sample Attempt
1
2
3
4
Bottle #
1
1
1
1
Sample #
1
1
2
3
Response Code
0
4
0
0
Volume stored (mL)
150
≤150
150
150
Response Code 0 = Successful Sample; Response Code 4 = Vacuum Time Out
Error
Summary of Contents for PVS5120 Series
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Page 70: ...Appendix A Sample Transport Velocity A 2...
Page 78: ...Appendix B Example Programs B 8...
Page 86: ...Appendix C Monitoring Sampler Status via RS 485 C 8...
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Page 100: ...Appendix H ISO5667 Conformity H 4...
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