在直读式铁谱仪中，用一根玻璃沉淀管来作为玻璃基片。制备在试管中的分析油样在重力和虹吸作用下，经过毛细管而进人沉淀管。油样中的铁磁性磨粒在沉积管下面的高梯度强磁场作用下，会有序地沉积在玻璃管底部。大于5μm的大磨粒首先沉积，它们一般沉积在沉积管的入口区；1～2μm的小磨粒沉积在较远处。在大、小磨粒沉积位置分别设置有光束发射装置，光束穿过沉积管，被设置在沉积管另一侧的光电传感器所接收，可以直接测定磨粒浓度的读数。

In a direct reading ferrography, a glass precipitate is used as a glass substrate. The analytical oil samples are prepared in the test tube under the action of gravity and siphon, through the capillary and into the precipitate tube. The ferromagnetic abrasive particles in the oil sample will be deposited in the bottom of the glass tube in an orderly way under the action of high gradient strong magnetic field under the deposition tube. More than 5 mu m large grains are first deposited, they generally deposited in the entrance area of the deposition tube; 1~2 m particles deposited in the distance. In large and small particles deposition position are respectively provided with a light emitting device, light beam passes through the deposition tube, photoelectric sensor is set on the other side of the deposition tube received, can direct determination of particle concentration readings.