Meriam M201 Rotary Gas Meter Tester - Manual (Page 3)

Addendum No. 9R124-IR
June, 2010
www.meriam.com
page 3 of 10
M201 Rotary (Natural) Gas Meter Tester
Periodic differential pressure tests, or “drop” tests, on
rotary natural gas meters are necessary to track meter
condition. The tests indicate changes in meter
performance over time and reveal when a meter
should be removed from service for repair or
reconditioning. “Slow” meters, those with higher
differential pressure, result in under-billing and
therefore cost the natural gas supplier money.
Meriam’s enhanced M201 has new features to improve
its general usefulness and make Rotary (Natural) Gas
Meter drop tests easier. The new Measure Mode
displays differential pressure readings while standing by
for a drop test. This allows users to make general DP
measurements and provides convenient feedback on
zero performance (simultaneously pressing the “Min/
Max” and
“Hold” keys takes a new zero when needed). Measure
Mode also lets users know when the M201 is correctly
connected to a meter and ready for a test to be run.
When a drop test is started, the enhanced M201 uses
an internal stop watch to time the test period. This
means the technician no longer needs to time the drop
test externally, he only needs start a test (press the
“Hold” key from Measure Mode) and then stop it
(press the “Hold” key again) after one meter revolution.
The M201 results screen shows the test period and
average DP once the test is stopped. To view the
minimum and maximum DP measured during the test,
simply press the Min/Max key. Toggle the Min/Max key
again to return to the test time and average DP results
display. The enhanced M201 includes a Mode Select
program menu for Legacy or Enhanced modes of
operation – the users chooses which mode is best for
them. See the “M201 Legacy and Enhanced Display
Comparison Table” on the last page of this Addendum
for more information.
New hardware options protect the M201 from one
sided overpressure. Options include a ¼ turn valve and
an integral push-to-read cartridge valve in addition to
the traditional push-to-read valve manifold. See the
Manifold Options section of this Addendum for more
details.