Operation instructions of Muffle Furnace

　马弗炉 说明书

The Muffle Furnace series produced by our factory are the innovated and upgraded products of the old ones, fabricated integrally, easy to install and operate, thus make the temperature control of the furnace more precise and automatic. It is widely applicable to all kinds of laboratories, industrial mining enterprises, scientific research units for element analysis and determination, as well as the heat treatment such as quenching, anneal and tempering etc of common small parts.

本厂制造的系列马弗炉是对老产品的改造和升级换代产品，一体化制作，使用安装方便,使电炉的温度控制精度更高、更自动化。广泛适用于各类实验室、工矿企业、科研单位作元素分析测定及一般小型件淬火、退火、回火等热处理作业。

Structural characteristics　结构特点
The exteriors of this series of resistance furnace are rectangular, the furnace outer plate is made of high quality cold-rolled steel sheets which are folding welded; the working chamber is made of high quality carborundum fireproof material, high quality thermal insulation material is filled between the furnace and shell for heat preservation. In order to preserve the heat at the furnace port and enhance the temperature evenness in the furnace, a hot baffle made of high quality fireproof material is mounted inside the furnace door.

本系列电阻炉外型均为长方体，炉壳采用优质冷轧钢板经折边焊接制成，工作室由优质碳化硅耐火材料制成，炉膛与炉壳之间用优质保温材料作保温层。为了减少炉口的热量散失，提高炉膛内温度的均匀性，在炉门内侧装有优质耐火材料制成的挡热板

Main technical parameters　主要技术参数：

1000℃ Muffle Furnace　1000℃马弗炉

1200℃ Muffle Furnace　
1200℃马弗炉

1300℃ Muffle Furnace
1300℃马弗炉

Installation and operation　安装与使用
1. This furnace is configured integrally, it needs no special installation, just put it on the ground or stand indoor. The furnace shall be grounded reliably for safe operation.
2. Power can be connected when the wiring is checked. First of all, turn on the power switch, then turn the toggle switch on the controller panel to On, turn the setting switch to Set, adjust the setting knob, set the temperature to your desired degree, then turn the setting switch to the position of measuring. At this moment, the red light is lit (ON), and there is also sucking voice from the contactor, the furnace is electrified, and the current meter indicates the value of heating current. The temperature will rise gradually along with the temperature rise in the furnace, which means that it works normally.
When the temperature reaches the set required temperature, the red light is off (ON), the green light is lit (OFF), the furnace will be powered off automatically, and the temperature stops rising. Later on, the green light is off, the red one is lit and the furnace is powered on automatically again when the temperature in the furnace drops a little. Moving in circles, for the purpose of automatic control of temperature in the furnace.
3. The heating power of silicon carbide rod type (type S) furnace shall match the desired temperature well. When the temperature in the furnace becomes constant, the green light is lit for a long time, it means the heating power is too big, you may adjust the heating power knob anticlockwise to reduce the value of heating current properly; if the red light is lit for a long time, it means the heating power is insufficient, and you may adjust the heating power knob clockwise to increase the value of heating current properly. If the alternate lighting time of red and green lights is relatively identical, it means the power matches well and the adjustment effect is nice. In order to reduce overheat during temperature rise, you may adjust the heating power knob anticlockwise to reduce the value of heating current properly when the temperature is about to reach the set temperature. Considering that the controllable silicon component is easy to be damaged when the current real varies, the heating power knob shall be turned anticlockwise to the limit prior to switching on/off the furnace, making the current rise or drop slowly.
4. In order to check whether the coupling trip protective device works well, the method is: loosen one end of the thermocouple, at this moment the temperature measuring indication will rise to the top rapidly and the heating power will be cut off automatically, it means the coupling trip device works well; it can work normally when the thermocouple is connected again.
5. Regarding the furnace drying, when the furnace is used for the 1st time or used again after long time suspension, the furnace drying must be processed. The progress is as follows:
When the temperature rises from room temperature to 200℃ for 4 hours (open the furnace door, let the water vapor disperses)
When the temperature rises from 200℃ to 600℃ for 4 hours (close the furnace door)
When the temperature rises from 600℃ to 800℃ for 2 hours (close the furnace door)
6. After use, firstly turn the toggle switch on the control panel to OFF, then cut off the general power supply

1、本电炉为一体化设置，电炉不需特殊安装，只需平放在室内地面或台架上。为了操作安全，电炉均需可靠接地。
2、检查接线无误后即可通电，首先合上电源开关，然后将控制器面板上的钮子开关拔向开的位置，把设定开关拔向设定的位置，调节设定旋钮，把温度设定到你所需要的度数上，然后把设定开关拔向测量的位置上。此时红灯亮（NO），亦有接触器的吸合声响，电炉通电，电流表指示加热电流值。温度随炉内温度升高而徐徐上升，说明工作正常。
当温度上升至设定的所需温度时，红灯灭（NO）、绿灯亮（OFF）、电炉自动断电，停止升温。稍后，当炉内温度稍为下降，绿灯灭，红灯亮，电炉又自动通电。周而复始，达到自动控制炉内温度的目的。
3、硅碳棒型（S型）炉子的加热功率应与所需的温度值有较好的匹配。当炉内温度进入恒温阶段后，绿灯亮的时间长说明加热功率太大，可反时针方向调节加热功率调节钮，适当降低加热电流值；若红灯亮的时间长，说明加热功率不够，可顺时针方向调节加热功率调节钮，适当增加加热电流值。红、绿灯交替亮的时间比较一致，则说明功率匹配，调节效果良好。为减少升温过程中的超温现象，在温度将达到设定温度前，可反时针方向调节加热功率调节钮适当减小加热电流值。考虑到可控硅元件在电流实变时较易损坏，在开机和关机前应将加热功率调节钮反时针方向旋到底，使电流缓缓上升和下降。
4、为了检查断偶保护装置是否正常工作，其方法是：松开热电偶一端，此时测温指示迅速上升到最高点亦自动切断加热电源，则断偶装置良好，重新接好的热电偶后，可正常工作。
5、烘炉，当电炉第一次使用或长期停用后再次使用时，必须进行烘炉。其程序如下：
当室温 升 200℃ 4小时（打开炉门让水蒸汽散发）
当200℃ 升600℃ 4小时（关闭炉门）
当600℃ 升800℃ 2小时（关闭炉门）
6、使用完毕，首先将控制器面板上的钮子开关拔向关的位置，然后切断总电源开关

Repair and maintenance　维修与保养
Technical parameters of 马弗炉－技术参数、使用说明
1. The instrument shall be put in dry place with nice ventilation but without corrosive gas, the temperature of working environment is 10-50℃, and the relative humidity shall not be over 85%.
2. In order to ensure accurate measurement, direct current difference potential meter shall be used every year to collate the temperature indicator of type XMT temperature controller, for avoiding major errors.
3. Inspect regularly whether the wires are loose, the terminal(s) of AC contactor is(are) well, it shall be repaired in time whenever there is failure.
4. Regarding the silicon carbide rod type furnace, when the silicon carbide rod is discovered damaged, it shall be replaced by a new silicon carbide rod which is with same specification and similar resistance. When replacing, firstly, demount the shelters at both ends and the collet of silicon carbide rod, then take out the damaged silicon carbide rod, to be careful when install it, for the silicon carbide rod is easy to be broken. The parts of both ends exposed out of the furnace plate shall be equal, and the collet must be firm, make it well contact with the silicon carbide rod. The collet shall be renewed when it is gravely oxidated. The rifts at both installation holes of the silicon carbide rod ends shall be blocked by asbest rope. The furnace temperature must not exceed the highest working temperature 1350℃. The silicon carbide rod is allowed to work for 4 hours continuously at the highest temperature. When the furnace has been using for quite a long time, if it is discovered that the heating current cannot be increased even though the heating power knob is adjusted clockwise to the limit. It is far away from the rated value, and the required heating power cannot be reached, it means the silicon carbide rod is aged. In this case, the series-wounded silicon carbide rods can be changed to parallel connection, and it can still be used. It is not necessary to disassemble the silicon carbide rod but change the connection when changing the connection, and once the connection is changed, the heating power knob shall be adjusted slowly upon use, the heating current must not exceed the rated value.
5. When the user operates it according to above operation instructions, and during normal operation, it is really because of the product quality that it does not work normally, free repair and parts renewal up to product renewal will be served within one year. But the user must not disassemble or assemble it by himself before the manufacturer can determine the quality problem, otherwise all the repair charges shall be the user’s responsibility.

1、仪器应放在干燥通风、无腐蚀性气体的地方，工作环境温度为10—50℃，相对温度不大于85%。
2、为保证测量准确，每年应用直流电位差计校对XMT型温度控制仪的测温表，以免引起较大误差。
3、定期检查各部分热线有否松动，交流接触器的触头是否良好，出现故障应及时修复。
4、硅碳棒型炉子，发现硅碳棒损坏后，应更换规格相同并且电阻值相近的新硅碳棒。更换时先卸下两端保护罩与硅碳棒夹头，然后取出已损坏的硅碳棒，由于硅碳棒易断，安装时须小心，两端露炉壳外部分应相等，夹头必须紧固，使之与硅碳棒接触良好。如果夹头有严重氧化时应换新的。硅碳棒两端安装孔处的隙缝应用石棉绳堵塞。炉温不得超过最高工作温度1350℃。硅碳棒在最高温度下允许连续工作4小时。在电炉使用相当长时间后，如发顺时针方向调节加热功率调节钮至最大位置，加热电流仍上不去。距离额定值较远，达不到所需的加热功率，说明硅碳棒已老化。此时可将串联的硅碳棒改为并联，仍可继续使用。在改变接法时不必拆卸硅碳棒，只需改变接法，并且改变接法后，使用时要注意缓慢调节加热功率调节钮，加热电流值不得超过额定值。
5、用户能守上述操作规程在正常使用过程中，确因产品质量不能正常工作时，一年内免费修理，更换零配件，直至更换产品。但未经生产厂查明质量原则，用户不得自行拆装，否则由用户负责各项维修费