What's the difference between pachometer and tachometer?
Pachometer
Definition:
(n.) An instrument for measuring thickness, as of the glass of a mirror, or of paper; a pachymeter.
Example Sentences:
(1) An explicit solution to these equations giving true corneal thickness in terms of apparent thickness cannot be established, and an iterative procedure is used to develop a relationship for a number of different pachometer configurations.
(2) The corneal endothelial cell count and central corneal thickness of 20 eyes of patients with pigmentary dispersion syndrome and 20 age-, sex-, and refractive error-matched control eyes were investigated in a masked fashion with a specular microscope and a pachometer.
(3) The advantage of the electronic pachometer over the standard pachometer is that one is able to easily measure areas other than the central cornea with repeatable accuracy.
(4) Sixteen patients who had never worn contact lenses underwent measurement of their central corneal thicknesses with the standard corneal pachometer and a new electronic corneal pachometer.
(5) In the hands of trained user, the topographic pachometer proves to be an instrument of acceptable clinical precision (standard deviation = 0.006mm).
(6) Unlike ultrasonic pachometers, the laser pachometer has the advantage of being a noncontact method of evaluating corneal thickness, and does not require topical anesthesia; the trauma and anesthesia might alter corneal thickness by inducing epithelial edema.
(7) First comparisons with a usual slit lamp pachometer show a general agreement but a systematic difference of about 20 microns.
(8) The corneal thickness was measured with a Haag-Streit pachometer prior to cataract extraction and 4 days to 6 months after the operation.
(9) A computer-assisted laser pachometer was compared with two ultrasonic pachometers for intra- and interobserver error.
(10) Also, a small but significant negative correlation was observed between the central corneal curvature and the corneal thickness as evaluated by either pachometer.
(11) We found the Vida-55 pachometer measured corneal thickness accurately when the appropriate ultrasound velocity was used (SEM = 6 microns).
(12) The laser pachometer was found to have intra- and interobserver errors comparable to both of the ultrasonic pachometers.
(13) Monitoring was by means of the electronic digital pachometer and the photoelectronic keratoscope (PEK).
(14) Reliability was assessed by an analysis of variance (ANOVA) between repeated measurements for the electronic digital and the Humphrey ultrasonic pachometers.
(15) Although many ultrasonic pachometers are commercially available, little has been reported about their performance.
(16) The equations presented here may be generally applied to all optical pachometer configurations, can be used to estimate the relative contributions of various sources of error in pachometry and provide a basis for obtaining uniform absolute derivations of corneal thickness.
(17) Corneal edema was monitored with a slit-lamp biomicroscope and pachometer.
(18) These measurements have been correlated with histologic and pachometer measurements of corneal thickness.
(19) Corneal swelling was determined by the ultrasonic pachometer technique.
(20) Measurement precision was enhanced by using a modified optical pachometer and conducting two test procedures which were analyzed by a coupled exponential model.
Tachometer
Definition:
(n.) An instrument for measuring the velocity, or indicating changes in the velocity, of a moving body or substance.
(n.) An instrument for measuring the velocity of running water in a river or canal, consisting of a wheel with inclined vanes, which is turned by the current. The rotations of the wheel are recorded by clockwork.
(n.) An instrument for showing at any moment the speed of a revolving shaft, consisting of a delicate revolving conical pendulum which is driven by the shaft, and the action of which by change of speed moves a pointer which indicates the speed on a graduated dial.
(n.) An instrument for measuring the velocity of the blood; a haematachometer.
Example Sentences:
(1) Speed settings were recorded as percentages of the servomechanism's maximum tachometer feedback voltage (10 to 100% Vfb max).
(2) Speed settings were standardized percentages of each machine's maximum tachometer feedback voltage (0 to 100% Vfb max).
(3) Displays of a tachometer and a special timing device are large enough to be clearly visible on the film.
(4) A Grass polygraph and tachometer were used to record the applied pulses and nodal firing rates; simultaneous magnetic tape recordings were obtained and used for data analysis.
(5) This report describes a safe and inexpensive method of modifying a centrifuge lid so that calibration of the machine with a photoelectric tachometer is a simple and safe procedure.