Hangzhou Fuding Weighing Instrument Co., LTD

Development on 50t Direct Hanging Calibrating Facilities on Electronic Crane Scales

(9/29/2009 7:12:40 PM)

1. General description
According to , an electronic crane scale must be calibrated before delivery. As a specialized manufacturer, how to calibrate a big capacity product is always a difficult problem that cannot avoid. Usually factories use dynamometers, which have huge difference from actual appliance sistuation and normally lead to errors, so that measuring accuracy have been affected. The requirement for a set of hanging facilities of crane scales is in front of manufacturers out of a question.

2.Practical condition
Presently, it seems very simple to obtain the facilities: purchasing a suite of crane machines, designing a special utilized frame, having an enough large site, and owning sufficient money, then it is a piece of cake. However, it is not quite easy for us to establish a 50t hanging calibrating facilities in a workshop with small size as 7m*10m*8m(W*L*H).

3.Scheme
In such small room, if we choose 50ton crane facilities, the whole system will be big and heavy that is not practical. Besides, order quantities of 50t crane scales are not as many as that of 20ton and 30ton, and its utilization frequency is less than 20ton and 30ton too. So finally we have decided to use two 30ton cranes bearing the force of one 50ton. It not only meets requirement of calibrating a big capacity, but also avoids wasting sources and is suitable for daily needs.

4.Composition and features of the facilities
The whole set of facilities consists of two 30ton special crane frames and its picture is as attached.

A 30ton link and chain electronic crane has been installed in each frame respectivley, whose vertical post uses ￠400㎜ seamless steel by integral welding. According to theoretical calculation, each crane frame bears up to 80ton, so that the whole set of faciities has stability, reliability and sufficient ensurance during uploading.

The total height of a 50ton crane scale is about 2.3m, the height of 50ton weight piles is 1.5m, the minimum direct line length of hook and shackle is 3m or so, and a minimum length of electronic crane is nearly 2m, thus the total height is 7.3m. In order to facilitate installation and upload, we have lowed down weight area for 1m below ground, which has been made by 0.8m armoured concrete, to ensure safety and practicability of hoisting and uploading.

5. Calibration on site
On February 2009, the set of facilities has been uploaded and type evaluated by Institute of Metrology in Zhejiang Province, and the detailed report has been attached as below:
Measuring upload（2009.2.10.） Unit：kg

Weight m	Displaying data ↓ I ↑		Added weight ↓ △m ↑		Error ↓ E ↑		Revised error ↓ Ec↑		Maximum permissible error
200	200	200	10	12	0	-2		-2	±10
400	400	400	10	12	0	-2	0	-2	±10
2000	2000	2000	10	10	0	0	0	0	±10
5000	5000	5000	8	10	+2	0	+2	0	±10
10000	10000	10000	8	8	+2	+2	+2	+2	±10
15000	15000	15000	6	8	+4	+2	+4	+2	±20
20000	20000	20000	6	8	+4	+2	+4	+2	±20
25000	25000	25000	4	6	+6	+4	+6	+4	±20
30000	30000	30000	4	8	+6	+2	+6	+2	±20
40000	40000	40000	2	6	+8	+4	+8	+4	±20
50000	50020		12		+18		+18		±30

Quoted from Institute of Metrology in Zhejiang Province《Type-evaluation report on measuring instrument》

（CODE:LXX-2009020598）
After upload, a senior engineer of the institute has given a highly-positive remark of the facilities: "It is a concrete ensuring for quality control, and you are the very first company at least in ZheJiang Province, who has the 50t hanging calibrating facility."

6.Conclusion
We aim to do even more with less. Our time-honored brand is really worth of its quality. The successfulness of the 50t hanging crane scale calibration faciilties has provided us a firm foundation for quality control. We will fast supply any kind of high quality products with capacities up to 50ton anywhere in the world!

Hangzhou Fuding Weighing Instrument Co., Ltd
(formerly named as Hangzhou Fuda Electroinc Equipment Factory)
2009.5.4.(a speech at 2009 International Weighing Expo.)