Acid tester
AssigneeLeco Corporation
InventorGeorge J. Sitek
Life of this patent
Estimating the term…
Abstract
An instrumentthat determines the HF and the HNO.sub.3 concentration or other mixed acids or single acid of an acid bath measures the potential difference between a fluoride ion selective electrode and a reference electrode and the potential difference between a hydrogen ion selective electrode and the reference electrode. The electrode voltages are applied to a control circuit including a microprocessing unit for calculating and displaying the acid concentrations of the bath and for compensating for the nonlinearity of the measured voltages as well as the interdependence of the two voltages. Also, means are provided for calculating and displaying percent metal concentrations.
Claims21
An acid testing instrument for use in combination with electrodes which are fluoride ion and hydrogen ion selective for determining the constituent acid concentrations in a bath including hydrofluoric and another acid having free hydrogen ions comprising:
- circuit means coupled to said electrodes for providing digital output signals representative of the ion concentration detected by said electrodes;
- a microprocessor and interface circuit means coupled to said microprocessor for handling input and output data and control signals to and from said microprocessor, said microprocessor coupled to said circuit means for receiving said digital output signals wherein said microprocessor includes a central processing unit (CPU) and storage means, a read-only memory and a switch multiplexer having operator actuated digital switches therein permitting the operator to select system parameters for controlling said CPU to correlate and process said digital output signals in a predetermined manner to provide display output signals representative of the concentration of acids being tested;
- and
- display means coupled to said interface circuit means for receiving and displaying said display output signals as acid concentrations.
An acid testing instrument including a measurement vessel for receiving acid solutions and into which there is positioned measurement electrode means, said instrument comprising:
- means for supplying a calibration acid solution to said measurement vessel;
- means for supplying a standardization acid solution of different concentration than said calibration acid solution to said measurement vessel;
- means for supplying a specimen acid solution to said measurement vessel;
- and
- measurement control means coupled to said electrode means and to each of said supplying means for sequentially actuating said supplying means for filling said measurement vessel with calibration acid, standardization acid and finally, specimen acid and measuring the output from said electrode means for each solution to determine two points on an acid concentration and electrode output correlation curve for the different acid concentrations of the calibration and standardization acid solutions and using this data for providing calibration and standardization data used in the determination of the concentration of the specimen acid solution.
An acid testing instrument for use in combination with electrodes which are fluoride ion and hydrogen ion selective for determining the constituent acid concentrations in a bath including hydrofluoric and another acid having free hydrogen ions, said instrument comprising circuit means coupled to said electrodes for measuring the voltage output of said electrodes when said electrodes are immersed successively in a calibration acid solution of a known acid concentration and a standardization acid solution of a known concentration different than the concentration of said calibration acid solution and a specimen acid solution of unknown concentration, said voltage output being representative of acid concentration said instrument including memory means coupled to said circuit means for storing signals from said circuit means representative of the acid concentrations of said calibration and standardization acid solutions, display means coupled to said circuit means, and control means coupled to said circuit means and to said memory means and actuated by an operator to selectively recall from said memory means said signals and applying said signals to said display means for displaying the concentrations of said known acid solutions permitting an operator to determine the accuracy of the display by said instrument of said known acid solution.
An acid testing instrument for use in combination with electrodes which are fluoride ion and hydrogen ion selective for determining the constituent acid concentrations in a bath including hydrofluoric and another acid having free hydrogen ions comprising:
- first circuit means coupled to said electrodes for providing output signals representative of the ion concentration detected by said electrodes;
- second circuit means coupled to said first circuit means for receiving and processing said output signals according to a predetermined interrelationship of constituent acids included in said bath for providing display output signals representative of the concentration of constituent acids of said bath;
- operator programmable means for storing signals representative of a predetermined acid concentration limit for at least one electrode;
- said second circuit means including means for comparing said predetermined limits with the measured acid concentrations and for providing an alarm output signal in the event said limits are exceeded;
- and
- alarm output means coupled to said comparator means and responsive to said alarm signal to provide an operator alarm.
In an acid testing instrument for determining the constituent acid concentration in a bath including a solution of more than one acid, means for determining, in addition, the metal content by weight of said bath comprising:
- means for storing the weight of a known volume of bath employed as the specimen by said instrument;
- circuit means including sensing means immersed in said bath for providing signals representative of the concentration of acids in said specimen;
- correlating means coupled to said circuit means for correlating signals representative of the weight of the known specimen volume with said signals representative of acid concentrations provided by said circuit means to provide difference output signals representative of the weight of the metal content of said bath;
- and
- display means coupled to said correlating means for displaying the metal content.
The instrument as defined in claim 22 wherein said correlating means generates electrical signals in the form of:
- ##EQU7## for providing said output signals.
Dependencies are inferred from the claim text.