By keeping contact with instrument company to obtain the sufficient application technical support and repair service in time.
保持与仪器公司联系，以及时获得足够的仪器应用的技术支持。
2
The steelyard clepsydra, a special type of clepsydra, had been a chief time-keepinginstrument during the Sui-Tang period a nd the earlier stage of Northern Song dynasty.