Operation & Maintenance; Zero Adjustment; Minimum Flow; Flow Rate Table - Seametrics EX803 Instructions Manual

OPERATION & MAINTENANCE

Zero Adjustment

When the EX800-Series meter is powered up and there is
no flow, there should be no output pulses (or, if connected
to the FT430/440, flow rate should read "0"). If there are
pulses, it may be necessary to adjust the flow meter under
no-flow conditions after it has been installed. This should
only be done if the indicated flow is low, near the lower
cutoff.
Reverse Output Option
Status
LED
Status
LED
Zero
Zero
Adj
Adjust
Pins
Zero Adjustment
To perform the adjustment, after determining that there
is a full pipe with no flow, short between the two pins
marked "Zero Adjust". A red LED light will come on for
approximately 50 seconds and then go out. The zero
adjustment is completed.

Minimum Flow

As with any other flow sensor, there is a rate below which
the EX800-Series sensor cannot read. Check the table
below for the minimum flow rate detectable by the sensor
for a given pipe size.
Flow Rate (GPM)
Feet Per
Second
1" 1.5" 2"
Min 0.28
0.7 1.5 2.7
Max 20.0
49 110 196
Presence of Flow Indication. To assist in troubleshooting,
the "Status LED" has two blinking modes in normal
operation. When there is no flow detectable by the meter
(below minimum threshold) the LED blinks every 8.0
seconds. When there is detectable flow, the same indicator
blinks every 3.0 seconds (Pulses are being output when
indicator is blinking every 3 seconds).

Filtering

The software of the EX800-Series filters out electrical noise
and averages sudden variations in the flow to smooth the
output. It takes a matter of seconds for the flow sensor to
get up to full output when it is powered up or when flow
begins.
Seametrics • 253.872.0284
1 2 3 4 5 6
- -
+ +
Forward Power
Output
Nominal Pipe Size
3" 4" 6" 8" 10"
6 11 25 44 69
440 783 1760 3130 4900

Electrode Coating

Grease or other adhering, non-conductive materials can
stop flow detection if the electrodes become heavily coated.
To clean the electrodes, remove the sensor from the pipe
and gently scrub the electrodes (three silver bumps) on the
reading face of the flow sensor. A mild soap (dish washing
liquid for example) can be used to aid the cleaning process.

Calibration ("K-Factor")

The K-factor represents the actual number of pulses per
gallon the meter produces during a flow test. This number
can be entered into your electronic control to make it read
properly. If the EX800-Series meter is ordered with a tee
fitting, it is factory-calibrated in the fitting and the K-factor
is indicated on the side of the fitting (see diagram).
If the EX800-Series meter is ordered with a saddle or
weldolet fitting, find your K-factor in the chart below.
K-Factors: Saddles & Weldolets
3"
Schedule 40 64.061
Schedule 80 71.660
12"
Stainless
56.770
Steel (10S)
99
Stainless
64.061
7050
Steel (40S)
Copper
69.497
Tubing (L)
Copper
71.317
Tubing (K)
Brass Pipe 64.311
Duct. Iron
52.212
(Class 52)
NOTE: K-factors are in pulses/gallon. For pulses/liter, divide by
3.785
Be aware that K-factors derived using the K-factor calculator
will be expressed as pulses/'unit chosen' but will usually
need to be entered as pulses/gallon when used with other
equipment.
Page 12
EX800 - SERIES INSTRUCTIONS
10031295
K:158.42
EF81T-P200
Find your K-Factor Here
4" 6" 8"
37.297 16.498 9.552
41.278 18.276 10.460
33.329 15.024 8.774
37.297 16.498 9.552
39.632 17.757 10.193
40.620 18.403 10.576
37.781 19.166 9.505
33.961 15.393 8.648
10" 12"
6.073 4.285
6.663 4.717
5.618 3.980
6.073 4.241
6.579 4.565
6.825 4.768
6.073 4.241
5.639 3.935
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