低溫脆性沖擊試驗機

型號：BWD-C

國產低溫脆性試驗儀廠家  結構原理

A、本設備由制冷壓縮機主機體、加熱裝置、電子控制箱、冷卻槽、冷卻介質循環系統、自動報警裝置等部分組成。啟動制冷開關后，壓縮機開始工作，制冷系統進入正式工作狀態。制冷壓縮機連續不斷的工作，當接近設定溫度時，冷卻槽中的加熱裝置開始按比例提供熱量，用以平衡制冷系統產生的多余冷量，以達到恒溫的目的。攪拌可使冷卻槽內的冷卻介質不斷循環，使溫度均勻一致。

B、試樣夾持器

試樣一邊夾持4個試樣（橡膠類），另一邊夾持15個試樣（塑料類）。

C、沖擊裝置

沖擊裝置由沖擊錘和自鎖機構組成。

D、沖擊器

沖擊頭半徑為1.6?0.1mm；

沖擊時，沖擊頭和試樣夾持器之間間隙為6.4?0.3mm；

沖擊頭的中心線與試樣夾持器之間的距離為8?0.3mm。

國產低溫脆性試驗儀廠家  使用方法 

1接通電源，溫控儀和計時器顯示燈亮。 

2向冷井中注入冷凍介質（一般為工業乙醇），其注入量應保證夾持器的下端到液面的距離為75?10mm。 

3將試樣垂直夾在夾持器上。夾的不宜過緊或過松，以防止試樣變形或脫落。 

4按下夾持器，開始冷凍試樣，同時啟動時序控制開關（或按動秒表）計時。試樣冷凍時間規定為3.0?0.5min。試樣冷凍期間，冷凍介質溫度波動不得超過?1℃。 

5提起升降夾持器，使沖擊器在半秒鐘內沖擊試樣。 

6取下試樣，將試樣按沖擊方向彎曲成180?，仔細觀察有無破壞。 

7試樣經沖擊后（每個試樣只準沖擊一次），如出現破壞時，應提高冷凍介質的溫度，否則降低其溫度，繼續進行試驗。 溫度，如這兩個結果相差不大于1℃時，即試驗結束。 

技術參數:

1.控溫范圍：室溫-70℃（室溫≤25℃）

2.恒溫精度：?0.3℃       

3.降溫速度：0℃～﹣30℃    約2.5℃/min

﹣30℃～﹣40℃   約2.5℃/min

﹣40℃～﹣70℃   約2.0℃/min

4.最大外形尺寸：900?500?800mm（長?寬?高）

5.工作室有效工作空間：280?170?120mm（長?寬?高）    

6.可裝試樣數量：1

7.數字計時器數字計時器：0秒-99分鐘，分辨率1秒

8.冷卻介質：乙醇或其他不凍液

9.攪拌電機：8W

10.工作電源：220V--240V，50Hz，1.5kW

11.工作溫度:≤25℃

 Low temperature brittle impact testing machine
Model: BWD-C
Structural Principles
A、 This equipment consists of a refrigeration compressor main body, heating device, electronic control box, cooling tank, cooling medium circulation system, automatic alarm device, and other parts. After activating the refrigeration switch, the compressor starts working and the refrigeration system enters the official working state. The refrigeration compressor works continuously, and when it approaches the set temperature, the heating device in the cooling tank begins to provide heat proportionally to balance the excess cooling generated by the refrigeration system, in order to achieve constant temperature. Stirring can continuously circulate the cooling medium in the cooling tank, making the temperature uniform and consistent.
B、 Sample holder
Clamp 4 rubber samples on one side and 15 plastic samples on the other side.
C、 Impact device
The impact device consists of an impact hammer and a self-locking mechanism.
D、 Impactor
The radius of the impact head is 1.6 ? 0.1mm;
During impact, the gap between the impact head and the sample holder is 6.4 ? 0.3mm;
The distance between the centerline of the impact head and the specimen holder is 8 ? 0.3mm.
Usage method
1. Connect the power supply, and the temperature controller and timer display lights will turn on.  
Inject freezing medium (usually industrial ethanol) into the cold well in two directions, and the injection amount should ensure that the distance from the lower end of the clamp to the liquid level is 75 ? 10mm.  
3. Vertically clamp the sample onto the gripper. The clamp should not be too tight or too loose to prevent deformation or detachment of the sample.  
Press the gripper to start freezing the sample, and at the same time, activate the timing control switch (or press the stopwatch) to start timing. The freezing time for the sample is specified as 3.0 ? 0.5min. During the freezing period of the sample, the temperature fluctuation of the freezing medium shall not exceed ? 1 ℃.  
Lift the lifting gripper and allow the impactor to impact the specimen within half a second.  
Remove the sample and bend it 180 ? in the direction of impact, carefully observing for any damage.  
After the impact of 7 samples (each sample is only allowed to be impacted once), if damage occurs, the temperature of the freezing medium should be increased. Otherwise, the temperature should be lowered and the test should continue. When the temperature difference between these two results is no more than 1 ℃, the experiment ends.  
Technical parameters:
1. Temperature control range: room temperature -70 ℃ (room temperature ≤ 25 ℃)
2. Constant temperature accuracy: ? 0.3 ℃
3. Cooling rate: 0 ℃ to -30 ℃, approximately 2.5 ℃/min
-30 ℃ to -40 ℃, approximately 2.5 ℃/min
-40 ℃ to -70 ℃, approximately 2.0 ℃/min
4. Maximum external dimensions: 900 ? 500 ? 800mm (length ? width ? height)
5. Effective workspace in the studio: 280 x 170 x 120mm (length x width x height)
6. Number of samples that can be loaded: 1
7. Digital timer: 0 seconds to 99 minutes, resolution of 1 second
8. Cooling medium: ethanol or other non freezing liquid
9. Mixing motor: 8W
10. Working power supply: 220V -240V, 50Hz, 1.5kW
11. Working temperature: ≤ 25 ℃

傳熱介質

在試驗溫度下，能保持流動，對試樣無附加影響的液體均可作傳熱介質。這類傳熱介質通常使用乙醇，此外還有丙酮、硅氧烷等。

試驗報告

A本標準名稱或編號

B樣品的詳細說明及其來源

C使用的傳熱介質、致冷劑或其他降溫方式

D程序A:脆性溫度和試樣破壞現象

E程序B：規定的試驗溫度和試驗結果

試樣規格：

試樣的長度為（20.5?0.5）MM，寬度為（6.0?0.5）MM，厚度為（2.0?0.2）MM.

沖擊器

沖擊器頭部形狀和尺寸，沖擊器的質量為（200?20）g,其工作行程為（40?1）mm。沖擊裝置的彈簧在壓縮狀態下，沖擊器端部到試樣的距離為（25?1）mm。

低溫測溫計

采用最小分度不大于1度的低溫測溫計測量冷凍介質的溫度，可使用低溫溫度計、熱電偶、電阻溫度計等。低溫溫度計為內標式半浸的，以尾長150MM，浸入液體深度75MM為宜。

組成

設備由工作臺、升降夾持器、沖擊裝置、低溫測溫計、盛裝冷凍介質的低溫容器、攪拌器等部分組成。

升降夾持器

升降夾持器由夾持器和升降裝置組成

從試樣受沖擊部位，到夾持器下端的距離為（11.0加或等于0.5）mm。

沖擊裝置

沖擊裝置由沖擊器和沖擊彈簧等組成。

試樣要求：

試驗前，試樣應放置在標準實驗室溫度下調節至少3H，并在明亮的光線下彎曲試樣并檢查試樣表面，試樣表面應光滑，無雜質、損傷及微孔。成品應經打磨后裁制成相應尺寸。

試驗結果與處理

程序A

1、試樣出現破壞的最高溫度，就是該試樣的脆性溫度。

2、溫度值應精確到1度。

程序B

如果一組試樣中沒有任何1個試樣破壞，則試驗結果為無破壞。如果一組試樣中有2個或2個以上試樣發生破壞，則試驗結果為破壞。如果一組試樣中只有一個試樣發生破壞，則再次取3個新的完好試樣測試，3個試樣均未發生破壞則試驗結果為無破壞；否則試驗結果為破壞。

 Heat transfer medium

At the experimental temperature, liquids that can maintain flow without any additional impact on the sample can be used as heat transfer media. This type of heat transfer medium usually uses ethanol, in addition to acetone, siloxane, etc.

Test report

Name or number of this standard

Detailed description and source of sample B

The heat transfer medium, refrigerant or other cooling methods used by C

D Program A: Brittle Temperature and Sample Failure Phenomenon

E program B: specified test temperature and test results

Sample specifications:

The length of the sample is (20.5 ? 0.5) mm, the width is (6.0 ? 0.5) mm, and the thickness is (2.0 ? 0.2) mm

Impactor

The shape and size of the impactor head, the mass of the impactor is (200 ? 20) g, and its working stroke is (40 ? 1) mm. The spring of the impact device is compressed, and the distance from the end of the impactor to the specimen is (25 ? 1) mm.



Low temperature thermometer

Low temperature thermometers with a minimum division of no more than 1 degree can be used to measure the temperature of the frozen medium, including low-temperature thermometers, thermocouples, resistance thermometers, etc. The low-temperature thermometer is an internal standard semi immersion type, with a tail length of 150mm and a liquid immersion depth of 75mm.

form

The equipment consists of a workbench, a lifting clamp, an impact device, a low-temperature thermometer, a low-temperature container for holding the freezing medium, a stirrer, and other parts.

 

Lift gripper

The lifting gripper consists of a gripper and a lifting device

The distance from the impact site of the specimen to the lower end of the gripper is (11.0 plus or equal to 0.5) mm.

 

Impact device

The impact device consists of an impactor and an impact spring.

Sample requirements:

Before the experiment, the sample should be placed at a standard laboratory temperature for at least 3 hours and bent under bright light to inspect the surface. The surface of the sample should be smooth, free of impurities, damage, and micropores. The finished product should be polished and cut to the corresponding size.

 

Experimental results and processing

Program A

1. The highest temperature at which the sample fails is the brittle temperature of the sample.

2. The temperature value should be accurate to 1 degree.

Program B

If none of the samples in a group are damaged, the test result is considered undamaged. If two or more samples in a group fail, the test result is considered as failure. If only one specimen in a group is damaged, three new intact specimens shall be taken for testing. If none of the three specimens are damaged, the test result shall be considered as no damage; Otherwise, the test result will be destructive.