以往查验血沉时,化验人员需经常观察时间,在血液注入血沉管后一小时读出血沉率,如时间不足或超过时间,都影响读数的准确性。这里介绍一种简单的血沉定时呼叫器,计时开始后,绿灯点燃,一小时后,红灯点燃,绿灯熄灭,同时喇叭报警,提醒化验人员观察血沉。呼叫器电路见图1所示。呼叫器主要由单结晶体管和 R_3、C_2组成 In the past to check the ESR, laboratory personnel should often observe the time, one hour after the blood is injected into the ES tube, read the ESR rate, such as lack of time or time, affect the accuracy of the readings. Here is a brief introduction of ESR timing caller, the timing started, the green light, an hour later, the red light lit, the green light goes out, while the horn alarm, to remind laboratory staff to observe ESR. Pager circuit shown in Figure 1. The pager mainly consists of a single junction transistor and R_3, C_2