发明名称 |
Measurement of pH and specific ion concentration |
摘要 |
A microprocessor-controlled pH and ion concentration meter is disclosed with improved testing procedures. The meter can be tested for excessive internal bias current by measuring the potential (V1) when the meter is connected to a circuit a known voltage (E1) of low impedance and the potential (V2) when the meter is connected to a circuit of the same voltage source (E1) but of known high impedance and having the meter compare (V2-V1) to a preset limit value. The meter can be tested for low internal impedance by further measuring the potential (V4) when the meter is connected to a circuit of a second external voltage (E2) and the known high impedance (R1). The meter then calculates: (V4-V2) and compares that value to preset limits based upon E1, E2 and R1. Such limits can be derived as (Zo) (E2-E1) / (R1+Zo) where Zo is the minimum acceptable internal impedance.
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申请公布号 |
US5124659(A) |
申请公布日期 |
1992.06.23 |
申请号 |
US19900485329 |
申请日期 |
1990.02.20 |
申请人 |
FISHER SCIENTIFIC COMPANY |
发明人 |
FROLA, FRANK R.;SCHNEIDER, JOHN T. |
分类号 |
G01N27/416 |
主分类号 |
G01N27/416 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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