问题 问答题 简答题

热工仪表校验对标准仪器选用有何规定?热工仪表校验点如何确定?

答案

参考答案:标准仪器选用规定:

(1)标准仪器必须具有有效期合格证书。

(2)标准仪器测量上限应为被校表测量上限的1.2~1.6倍,特殊情况下,其测量上限也不应低于被校表的测量上限。

(3)标准仪器的允许误差绝对值应小于或等于被校表允许误差绝对值的1/3。

热工仪表校验点确定:

(1)0.5级以下至2.5级以上的仪表及变送器的校验点(包括上、下限及常用点)应不少于5点,流量测量仪表应不少于7点。

(2)0.5级及2.5级以下的仪表及变送器的校验点应不少于3点。

阅读理解

In the early hours of March 8, a Boeing 777 took off from Kuala Lumpur, Malaysia. Its destination was Beijing. But for unknown reasons, it never arrived there.

There were 239 people on the Malaysia Airlines flight, including 154 Chinese. As of March 13, 12 different countries, including Malaysia, China, Vietnam and the US, were searching for the plane.

The disappearance is an “aviation (航空) mystery”, Azharuddin Abdul Rahman, the head of Malaysia’s Civil Aviation Authority, said on March 10.There was no clear sign of a crash by March 13.

Between 1-2 hours after takeoff, the plane suddenly lost contact with people on the ground. The weather was clear, and the pilots didn’t make any calls . No evidence was found in the area where the flight last made contact. People are also talking about a possible hijacking (劫机).

International police agency Interpol confirmed on March 9 that at least two passengers on the flight had used stolen passports to get on board. “We are looking at all possibilities,” said Malaysian Transport Minister Hishamuddin Hussein. The incident is now being called simply a “plane disappearance”.

So, what are some possible causes of a plane disappearance? An AP story provided a summary.

1. A failure of the plane’s body or its engines. However, even if both engines stopped working, the plane could still glide (滑翔) for up to 20 minutes, giving pilots time to make an emergency call.

2. Bad weather. Planes are designed to fly through most severe storms. However, in June 2009, an Air France flight from Rio de Janeiro to Paris crashed during a bad storm over the Atlantic Ocean.

3. A bomb. Throughout history, several planes have been brought down by bombs.

4. An accidental shoot-down by some country’s military. In July 1988, the US Navy accidentally shot down an Iran Air flight. In September 1983, a Korean Air Lines flight was shot down by a Russian fighter jet.

No matter how unlikely a situation, it’s too early to determine what really happened to MH370. It could take months, if not years, to rule out any possibilities, say experts..

小题1:How many cities are mentioned in this passage?

A.Four cities.

B.five cities.

C.Six cities.

D.Seven cities.小题2:What could the underlined phrase “rule out” in the last paragraph mean?

A.cross out

B.get rid of

C.take out

D.take the place of小题3:What could be the best title of the passage?

A.An Air Crash

B.The Causes of the Disappearance

C.The Disappearance of MH 370

D.An Aviation Mystery

单项选择题 A1型题