ULTRASONIC GAS METER

Gas meter is one of the most important equipments in the city gas industry not only because counting gas consumption accurately but also providing safety services to customers. The ultrasonic smart gas meter, introduced in this page, inherits long history of intelligent gas meter development in Japan, which started back in 1970s.

 

Micon-Meter

マイコンガスメーター
Conventional Micon-meter: positive displacement flow meter with safety functions.

“Micon-meter,” the conventional intelligent gas meter makes use of the positive displacement technology to measure gas consumption, and is equipped with other safety capabilities, including seismic shutdown, low pressure shutdown, excessive flow shutdown, and leak indicator. Ultra low power consumption of electric circuitry in the meter was a major technical challenge  as the internal battery has to last for 10 years.

 

Shut-Off Conditions of Micon-Meter

  1. Leaks more than 3L/hour
  2. Excessive flow rates
  3. Prolonged gas usages
  4. Earthquakes
  5. Pressure drops

The micon-meters have been widely used in the city gas and propane gas industries in Japan, and it become an indispensable device in enhancing customer’s safety.

 

 

Development of Ultrasonic Gas Meter

New Features

Ultrasonic gas meter (maximum flow rate of 6m3/h)

 A new gas meter employing variety of the cutting-edge technologies has been developed by the initiative of Tokyo Gas, aiming to play an important role in the IT era. The new meter employs the ultrasonic principle for gas flow measurement, and communication and data logging capabilities are also equipped.

 

 

 

 

 

 

Tele-metering & Tele-controlling, and data logging ?

The ultrasonic smart gas meter is capable of tele-metering & tele-controlling using optional data communication terminals. The tele-metering function is not limited to the monthly meter reading but also sending gas consumption log data, pressure log data, and alarm information. The tele-controlling function is mainly used for the remote shutoff upon telephone requests from contracted customers.

 

High reliability, Small and Lightweight

Simple structure with no moving mechanical parts helps to reduce costs, and make the meter small and lightweight.

Size comparison between two meters

 

Width

Depth

Height

Weight

Ultrasonic meter
(Qmax: 1.6 - 6m3/h)

170mm

85mm

140mm

2kg

Diaphragm meter
(Qmax: 6m3/h)

195mm

156mm

324mm

4kg

 

 

 

 

 

 

 

Universal design for Methane/Propane gas metering

Because the flow path has been designed to minimize the difference on gas composition, the gas meter can also be used for liquefied propane (LP) gas metering.

  

 Meter Construction and Measurement Principle

 

 

1. Ultrasonic waves are transmitted from the upstream sensor to the downstream sensor, and the transmission time (T1) is measured.
2. Ultrasonic waves are transmitted in the opposite direction, and the transmission time (T2) is measured.
3. The velocity of gas flow (U ) can be obtained from the difference between the two times using the equation above.

 

 

 

SPECIFICATIONS

Maximum flow rate

1.6m3/h, 2.5m3/h, 4m3/h, 6m3/h

Minimum flow rate

80L/h

Detectable minimum leak

3L/h with in a month

Operating temperature

-25 ~ 60 degrees centigrade

Operating pressure

0 ~ 3.5kPa

Pressure loss (air)

< 190Pa at 6m3/h

Power supply

Lithium batteries

Battery life

10 years or more

Shut-off valve

Open/close 2 way valve driven by stepping motor

Telecommunication port

A 300 bps port & an alert system interlocking port

Self-diagnostics functions

1. Low battery
2. Ultrasonic sensor error
3. Valve leakage

Logging function

1. Hourly gas consumption or gas pressure profile
2. Up to 3 time zones per day for time based multilevel tariff

 

CURRENT STATUS

More than 25,000 ultrasonic gas meters have been installed during over 2 years of a pilot introduction program; it has proven that the ultrasonic gas meter is not only sufficiently reliable but also competitively priced compared to conventional diaphragm type gas meters.

Tokyo gas, Osaka gas, and Toho gas have collaborated in the development of the ultrasonic gas meter.

More information contact: netdecheck@tokyogas-es.co.jp

 

 

© 2005 TOKYO GAS ENGINEERING SOLUTIONS CORP. all rights reserved.