4220 Flow Meter
Section 2 Programming
control. There are several possible
Flowlink is Isco's proprietary data acquisition and management software. Flowlink works with personal computers, modems, and laptop computers to monitor flow meters from a distance. Consult the factory for more details about Flowlink.
VOLUME makes the flow meter pace the sampler after a spe- cific volume passes through the stream.
CONDITIONAL allows pacing of the sampler by the flow meter when a particular condition has been met, or has changed. Among these conditions are changes in level, flow rate, temper- ature, rainfall, (if you are using the optional rain gauge sensor), D.O. (dissolved oxygen), or pH. You can also use a pair of condi- tions, or if you are using the YSI 600 sonde, you can select mul- tiple conditions from its sensors.
Note
| If you choose CONDITIONAL for sampler pacing and it doesn’t |
| seem to work properly for you, read the section on hysteresis. |
| Then check the hysteresis setpoints for your conditions. (The |
| defaults are all zero.) |
| You must have the appropriate sensors attached to the flow |
| meter to measure temperature, D.O., pH, conductivity, etc.; the |
| flow meter cannot do this by itself, nor does it occur automati- |
| cally. |
2.3.6 Step 6 - Sampler | Sampler Enable means that in a combination flow |
Enable | meter/sampler pair, the flow meter controls the sampler's ability |
| to run its own program. The difference between step 5, sampler |
| pacing, and step 6, sampler enable is that in sampler pacing, the |
| flow meter merely sends flow pulses to the sampler from time to |
| time. The sampler counts these flow pulses to determine when to |
| take a sample (according to its own programming). |
| With sampler pacing, the sampler is always enabled. With |
| sampler enabling, the flow meter can actually stop operation of |
| the sampler. The sampler is still set up to run its own program, |
| but the inhibit/enable line from the flow meter will determine |
| when and whether the sampler runs its program. This feature is |
| useful for storm water runoff monitoring applications, where it |
| may be necessary for the flow meter/sampler pair to have to wait |
| a long time between storm intervals. |
| Again, changing or meeting a condition or set of conditions |
| triggers the enabling. The conditions that can be used for |
| sampler enabling are similar to those used for sampler pacing: |
| level, flow rate, rainfall, temperature, dissolved oxygen, pH, or a |
