15
The TC options, when metric units of measure are the default, include the following:
• Diaphragm TC: Click on Diaphragm TC when testing a TC diaphragm meter.
• ROOTS Mechanical TC: 8C-3M – Click on ROOTS Mechanical TC when testing a
ROOTS 8C, 11C, 15C, 2M or 3M meter.
• ROOTS Mechanical TC: 5M-16M – Click on ROOTS Mechanical TC when testing a
ROOTS 5M, 7M, 11M or 16M meter.
• ROOTS Electronic VTC: Click on ROOTS Electronic VTC when testing the ROOTS VTC.
• ROOTS Electronic IMC: Click on ROOTS Electronic IMC when testing the ROOTS IMC.
If you choose TC or PCTC for meter output, the box labeled “Base Temp. Corr. °F” will appear.
Manually enter the desired base temperature, then press <Enter>. Using the default units of measure,
the acceptable range of temperatures is 32°F to 80°F (0°C to 30°C).
Test results may be affected below 40°F (4°C).
5.4 Drive Rate or Pulses Per Test (PPT)
Refer to Configuring Tests for additional information on selecting proper values for the
Drive Rate and Pulses/Test
If you select the Instrument Drive (ID) Pulser as the Test Control Mode, the box labeled Drive Rate cf
will be displayed on the Configure-Run Meter Test screen. Drive Rate is the volume of gas that passes
through the meter for each revolution of the ID Pulser. The Drive Rate usually corresponds to the odometer's
base increment. It is typically specified on the drive, the meter, and/or the device mounted to the instrument
drive unit. See Table 1 on page 14 for ROOTS
®
Rotary Meter Drive Rates.
Never use partial revolutions as erratic proofs may occur.
Displayed values for Drive Rate have a corresponding valid Test Volume value(s) for the particular
Master Meter being used. However, use of the Optical Scanner as the Test Control Mode requires
you to calculate, enter or select valid entries.
If you select the Optical Scanner option as the Test Control Mode, the Pulses/Test box will be displayed,
instead of Drive Rate. When the optional Optical Scanner is used for a meter test, you must determine the
total pulses that the Optical Scanner will send back to the Controller for the entire test's duration. If a
fractional number is entered into the Pulses/Test box it will be rounded up to the nearest whole number.
See Table 2 on page 14 for ROOTS
®
Rotary Meter Pulses/Test Values.
An entire test's duration is from the start of the test until the first "Test # Complete" message is displayed on
the Meter Test screen. A basic relationship exists between a Field Meter’s gear ratio and its measured volume
or its odometer's base increment. The odometer's base increment typically corresponds to the meter’s Drive
Rate, for meters with no Instrument Drive unit. If both the gear ratio and the odometer's base count are
known, the proper whole number for the Pulses/Test and the proper Test Volume may
be determined.
Changing the Drive Rate or Pulses/Test
For both the Drive Rate and Pulses Per Test, click on the black arrow on the right-hand side of the box to
display the drop down menu. Select from the default values. Choosing “Other” will allow you to manually
enter the Drive Rate or PPT into the box immediately to the right and allow you to type in the new Drive Rate
or PPT, or click on the up/down arrow button to change the number displayed. Press <Enter> once the
appropriate value has been selected.
