{_ComName}

(1) After completing the electrocardiogram every day, keep the electrodes clean. If rust spots appear on electrodes made of copper alloy, the rust spots can be wiped off with fine sandpaper and then soaked in physiological saline overnight to form a stable film on the surface. The silver-plated electrode can be washed and dried with water to avoid scratching the silver-plated layer.

(2) The core wire or shield of the lead cable is easy to break and damage, especially near the joints at both ends. Do not pull or twist with force. When storing, it should be coiled or hung with a larger diameter to avoid excessive twisting or acute angle folding .

(3) The AC and DC electrocardiograph should be charged in time according to the instructions to extend the battery life.

(4) The electrocardiograph should avoid high temperature, sunlight, moisture, dust or impact, and cover the dust cover after use.

(5) Open the cover regularly for dust removal, dehumidification and inspection. Remove the dust in the circuit board in time to ensure that the inside of the machine is dry to avoid short circuit caused by moisture or dust and damage to the circuit board.

(6) The performance of the ECG machine is regularly checked by the quality and technical supervision department.

Common faults and repairs

(1) Interference

When the electrocardiograph is in the working state, interference waveforms of various frequencies will appear during paper recording. Causes Poor contact of organic parts, faulty grounding, strong electromagnetic fields nearby, etc. Check each connection line and eliminate the fault after eliminating nearby interference.

(2) Jitter

When the lead selection switch of the electrocardiograph is set to the "0" (1mV) position, the hot pen traces an irregular waveform, which is jitter. The causes are: the AC and DC power supply voltage is unstable, causing changes in the operating points of the amplifier at various levels; the pressure adjustment of the hot pen is unqualified; Failure, poor contact of the potentiometer, poor contact of the printed plug and socket, and soldering of components and pins.

(3) Poor linearity

When the hot pen is at different positions, the amplitude of the 1mV voltage rectangular wave recorded is quite different, that is, the linearity is not good. The causes are: bad mechanical parts of the hot pen, malfunction of the recorder, and the operating point of the power amplifier is not adjusted properly.

(4) Abnormal damping

The excessively large or rounded corner of the 1mV voltage rectangular wave is under-damped or over-damped. The causes of over-damping are: the pen pressure is too heavy, the pen temperature is too low, the potentiometer of the damping circuit is not adjusted properly, and the pen holder is too low or too high. The causes of underdamping are: the pen pressure is too light, the pen temperature is too high, the potentiometer of the damping circuit is not adjusted properly, and the recorder loses magnetism.

(5) The sensitivity is too low

In the 10mm / 1mV sensitivity section, the sensitivity potentiometer cannot be adjusted to 10mm / 1mV. The main causes are: the AC power supply voltage is too low, the DC voltage stabilization circuit inside the machine is faulty, the transistor, the integrated block or the resistance-capacitance component in the amplifier is deteriorated, the operating point of the amplifier is incorrect, and the recorder coil is locally short-circuited.

(6) Waveform distortion

Causes: Improper damping adjustment or faulty damping circuit, poor linearity of the recorder, deterioration of resistance-capacitance coupling capacitance, deterioration of components of the EMG suppression network and 50Hz suppression network, loss of input balance resistance, interruption or resistance deterioration, voltage amplifier and The working point of the power amplifier is not adjusted properly, and the paper feed pushing device is faulty, causing an excessive paper feed speed error.

(7) The battery pack cannot be charged

Nickel cadmium battery is a kind of battery that can be recharged repeatedly. Generally it can be charged and discharged 300 to 500 times. The rated voltage is 1.25V and the terminal voltage is 1.1V. There are the following reasons for the failure to charge: the output switch of the charging circuit is not placed in the charging position, the lead of the battery pack is dropped, the number of charging times reaches the rated number, the battery fails, one or more of the battery packs have deteriorated, the charging circuit is defective, the machine There is a problem with the internal power circuit.

(8) The fuse is blown

The fuse blows mainly due to the following reasons: some of the transformer's primary coils are short-circuited due to poor insulation, there is a short-circuit in the power supply inside the machine, and the high-power regulating tube in the voltage regulator circuit has poor or short-circuit insulation to ground.