升級版砼限制膨脹率測定儀（自動、手動可選）

Device name：Upgraded Horizontal Shrinkage Expansion Instrument
Model：YC-HSP540D
Origin：Peking
Purpose：A special instrument for measuring the change of length (volume) of concrete specimens during hardening under certain environmental conditions.

現有限制膨脹率測定儀存在如下不足：
（1）標準中校準桿材質建議選擇硬鋼或石英玻璃材質制作，但目前市場上的校準桿基本上都為不銹鋼材質，不銹鋼校準桿的線膨脹系數很大，易因溫度波動影響造成誤差。
（2）千分表精度差，即使選用業內較好的電子千分表也有±3um的測量誤差，一般的千分表誤差在±5um以上，這對于混凝土試件后期收縮量本來就很小而言，會造成很大的誤差。
（3）試驗過程人工讀數記錄，易因人為筆誤或在數據抄寫過程中失誤造成錯誤。
并且，由于在整個試驗周期中，同一個試件要測量十幾次，上述3種誤差因素會被不斷放大，很有可能出現前后試驗結果相互矛盾的現象，且無法找到問題根源。 

The shortcomings of available horizontal concrete shrinkage expansion meter:

(1) Hard steel or quartz glass is recommended for the calibration rod material in the standard, but the available calibration rod in the market is mostly made of stainless steel. Its linear expansion coefficient is too high, which is easy to cause errors due to the influence of temperature fluctuation.

(2) The accuracy of the micrometer is poor, even if the best electronic micrometer is used, because its measurement error is more than 3um. Generally, the error of the micrometer is more than 5um, which will cause a great error for the shrinkage of concrete specimens in the later period.

(3) Manual reading records during the test process are prone to errors, which is caused by human errors or errors in data transcription.

Moreover, the same specimen needs to be measured more than a dozen times in the whole test cycle. The above error factors will be enlarged continuously, and it is likely that there will be conflicting phenomena between early and later results. We can’t find the root cause of the problem.

Features:

1. More accurate: With the help of high-precision displacement sensor and invar calibration rod, the measurement error is less than 1um, which ensures the accuracy and comparability of long-term test results.

2. No needs for long-term on-line observation. Testing at the age can improve the efficiency of the equipment.

3. There is no need to record manually during the test process. All the data are stored in the test host. All results could be derived by the user through U disk, and then can be viewed by Excel.

4. The test results are marked by operators, and the test time, temperature and humidity of the test environment, specimen number, age and length are recorded at the same time.

5. The device has the function of permission setting, and the non-operator can’t log in, which ensures the safety of the test results.

Parameters：

Model:  YC-HSP540D

Measurement range of tester: 538-542mm

Measurement range of sensor:0-2mm

Error in measurement: ≤1um

Resolution：0.1um

Invar calibration cod: 540±0.1mm

Error of temperature sensor：≤0.5℃

Measurement range of temperature sensor：0-50℃

Error of humidity sensor: ≤3%RH

Measurement range of humidity sensor: 0-99%RH

Specimen size: 100×100×515mm

Host size: 370×340×240mm

Dilatometer bench size: 670×240×180mm

Power supply：AC220V/AC 110V