RATE
MEASUREMENT
Rate Measurement measures
the input rate. This measurement defaults to show in Hz (pulse/sec), but
may also show in kHz, RPMs (for tachometer applications), feet/seconds,
or other engineering units.
LINE
FREQUENCY MEASUREMENT
Line frequency measurement is useful as a self-test of the meter.
A signal equal to twice the line frequency is internally available.
Close the S1-9 and S1-4 switches and set the scale factor to multiply
by 0.5 (or divide by 2) to measure line frequency. The display shows "50"
or "60", depending upon your local ac line frequency.
Note: No external connection to TB2 is necessary.
REVOLUTIONS PER MINUTE (RPM)
MEASUREMENT EXAMPLE
Example: 10 pulses per revolution
A sensor generates ten pulses for every revolution of a shaft.
If n pulses per revolution is generated, use the following formula:
|
SCALE
= X/n
|
X
=
|
1
for units/seconds (e.g. Hz) |
| |
|
60
for units/minutes (e.g. rpm) |
| |
|
3600
for units/hours (e.g. GPH) |
| |
n
=
|
pulses/units
(gallons, revolutions, feet) |
To measure the input
frequency and show in RPM (instead of Hz), set the SCALE FACTOR to 60/10,
or 6.
In this example you will do the following:
* Set function to rate mode
* Set scale to use "multiply by"
* Set scale value to 6.00000
* Set measurement decimal point to fixed, far right position
* Store set up information in nonvolatile memory
Refer to Table 6-1 for summary list of menu configurations.
To set up the meter for this example, follow these steps:
1. Press the MENU button. The meter shows "Func".
2. Press the MENU button. The meter shows "SCALE".
3. Press the 
SET button. The meter shows "IN .SC" or "IN/SC", with the multiply
(.) or divide by (/) symbol flashing. Press the
SET button until the meter shows "IN .SC".
4. Press the 
ADV button. The meter shows actual scale value, with left-most
digit flashing. The flashing display indicates the position or function
may be modified.
5. Set the value at "6.00000". Press the
ADV button to move through the display. Press the
SET button to change the flashing digit's value or flashing decimal
point position.
6. Once the meter shows the correct scale value, press the MENU
button to store to volatile memory. The meter shows "OFFSEt". "OFFSEt"
= 0 for all flowmeters where: 0 Hz = 0 GPM or RPM. For flowmeters with
an "OFFSEt", enter the "OFFSEt" in engineering units, such as GPM or LPM.
7. Press the MENU button again to show "dEC Pt". This is
the measurement decimal point, not the scale value decimal point.
8. Press the
SET button to show current measurement decimal point, with decimal
point flashing. Press the
ADV button (if required) to change from "AUto" to "F.FFFFF".
9. Press the
SET button until the meter shows "FFFFFF".
10. Press the MENU button to save this decimal point to
operating memory. The meter shows "COnFIG". If a relay card is installed,
the meter shows "SP LO".
11. Press the MENU button again until the meter shows "no
Stor".
12. Press the
SET button. The meter flashes "StorE".
13. Press the MENU button to store changes in the nonvolatile
memory. The meter stores changes. If this were a real application (not
the example), the meter would start measuring.
NOTE: If you connect a signal to an input, a frequency reading
in RPM replaces this display.
|
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