With this method, the number of complete pump cycles per minute is
fixed, within a range of 1 to 6; 4 CPM is the default value which ap-
pears at startup. Each time the up/down arrow keys are pressed, the
pump refill and discharge times are both automatically adjusted to
maintain the selected CPM value. Each adjustment increases or de-
creases the volume pumped per cycle, and the per-minute flow rate is
the volume per cycle X the CPM value.
OPERATION
8
For example, with a 4 CPM setting, 60 ml volume per cycle equates to
4 X 60 = 240 ml/min flow rate. A single press of the Flow up-arrow
key could change the volume per cycle to 80 ml, for example, resulting
in a new, increased flow rate of 4 X 80 = 320 ml/min. And the MP10
assigns a unique identification value to each setting, the ID value, which
can be directly set during later sampling events.
"MP" displayed in the lower left corner of the display indicates Micro-
Purge mode. The default CPM setting of 4 cycles per minute is a good
starting point for wells with depths from 25-100ft. MicroPurge mode
starts at a time setting of 10 seconds refill and 5 seconds discharge,
close to optimal for many wells. This startup settings corresponds to a
4 cycles per minute setting (CPM4) and an ID setting of 103.
Using the CPM key will change the CPM setting on the controller. The
range of CPM settings is CPM1 through CPM6. CPM changes like this
each time you hit the CPM key: 4 5 6 1 2 3 4 5, etc. The UP and
DOWN keys change the flow rate directly, by altering the refill and dis-
charge times
within
a CPM setting.
Note: changes in settings that are
entered while the controller is cycling are reflected on the next cycle
change (so a long refill time of 15 seconds will time out before a new
refill time becomes valid).
Here is an example of the use of the UP (faster) key:
Refill
Discharge
ID
(sec)
(sec)
Key Press
---
1
2
3
10.0
9.5
9.0
8.5
5.0
5.5
6.0
6.5
103
104
105
106
