Vacuum oven why must first vacuum and heating, instead of heating up and then vacuum?
1) products into a vacuum box vacuum to gas is pumped to the product material can be pumped to the component. If the first heating products, gas heat expands. Because the vacuum box sealing performance is very good, the huge expansion pressure generated gas is likely to make an observation window toughened glass burst. This is a potentially dangerous. According to the first vacuum heating again operating procedures of heating, so that you can avoid the danger.
2) if the operation procedures according to the first heating and vacuum pumping, when heated air was vacuum pump out the heat will be brought to the vacuum pump to vacuum pump, resulting in excessive temperature rise, may make the vacuum pump efficiency drops.
3) gas heated by guiding the vacuum pressure gauge, temperature rise will produce vacuum pressure gauge. If a temperature rise over the vacuum pressure gauge using the specified temperature range, may make the vacuum pressure shown value error table generation.
The correct use of the method should be the first vacuum heating up again. To achieve the rated temperature found after vacuum degree decreased again when appropriate and twitch. Doing so is beneficial to prolong the service life of equipment.