Time calibration

NOTE Time calibration 5 milliseconds for both traces. Intracellular amplitude, calibration 10 mV. 

NOTE Following amphetamine, the intracellular postsynaptie potential (PSP) is reduced as is PI in the field potential. A reduction in the latency to and a modification in components of the rebound potential can also be observed. Time calibration 50 milliseconds. Intracellular amplitude 5 mV. 

Retention time calibration. In spite of all effort to obtain reproducible retention time values these varied for the same component between different chromatographic runs, mainly because of different sample amounts. To solve this problem all retention time values were calibrated. Values for a limited number of peaks, that could easily be found in all the chromatograms in a set, were manually entered into the computer. For each of these reference peaks the mean value M j) over all the runs was calculated. New retention tim.es, Rtcal(i), for the peaks in the data set were then calculated by the straight-line expression ... 

The time scales of modem oscilloscopes are highly accurate. Furthermore, they carry internal standards for time calibrations to check their timing accuracy. Cole (Ref 1, Chapt 5) devotes... 

The pulses produced by this action proceed thru mixer circuits to an oscillograph where they are displayed on a cathode-ray oscilloscope screen along with time calibration markers. This display is photographed and detonation rates are computed from expl increment lengths, and measurements of time displacements are read on a film reader... 

The basic components of an HPLC system are (1) a pump with a constant flow control (2) a high-pressure injection valve (3) a chromatographic column (4) a detector and (5) a strip-chart recorder or a data system for measuring peak areas and retention times. Calibration standards are prepared at various concentrations and the retention times and peak areas of the analytes are compared against the standard solutions of analytes for their identifications and quantitations. 

The required results of the retention time calibration and performance test are as follows ... 

In investigating electrode processes it is extremely important to know whether the assumptions of the theory that is being applied are valid. Calibration of the working electrode and of the cell is thus a fundamental requirement. Since electrode response varies with time, calibration may have to be repeated fairly often. 

The time scale of the MCA spectrum has to be calibrated. In analogue systems this can be done by (a) using a commercially available time calibrator (b) stopping the TAC-MCA clock with a delayed start pulse, then introducing an extra known delay and measuring the change in channel... 

The polystyrene sizes were not the sizes commonly assumed for polystyrenes based on extended chains, but instead were determined from the viscosities (measured by Arro Labs, Joliet, Illinois) as described in Reference 8. Other types of standards and methods of calibration have been used for the GPC of residua samples (3, 9), including the Benoit universal calibration (10). However, these all relate the molecular weight to elution time, and for this work a molecular-size-elution-time relationship was needed. The polystyrene and n-alkane sizes were used to construct a In size vs. elution time calibration that was fit to a fourth-order polynomial to give a smooth curve. 

Although °Th has found widespread use as a CFP, applications are limited by its 75 ka half-life to sediments deposited during the past —300 ka. Paleoceanographic research would clearly benefit from a CFP that can be applied further back in time. Calibration work is underway to determine the suitability of extraterrestrial He, contained in interplanetary dust particles (IDPs), as a CFP that may be applied to much older sediments. 

The amplified signals from the crystals—the four gages were connected in parallel —were impressed on the horizontal-deflection plates of the cathode-ray tube. The screen of the tube was photographed with a rotating-drum camera. The drum ran at a uniform speed and, therefore, the time base was linear. Time calibration was obtained by means of a flashing neon crater tube (Sylvania, Type R1130B) which was activated by a 1000-cycle tuning-fork oscillator. The crater tube was in the... 

Intermediate precision. Intermediate precision expresses within-laboratories variations different days, different analysts, different equipment, etc. [13]. The ISO definition used the term M-factor different intermediate precision , where the M-factor expresses how many and which factors (time, calibration, operator, equipment or combinations of those) differ between successive determinations [17]. In a strict sense, intermediate precision is... 

The space-time pattern of Cerenkov wavefront can be reconstructed during off-line analysis fitting relation 9. The reconstructed muon direction will be affected by indetermination on PMTs position (due to underwater position monitoring) and on hit time (PMT transit time spread, detector timing calibration,...). 

Even irradiation of sample area Short exposure time Calibrated photometers usually available Small sample area... 

Specific chemical scrubbers which are switched into the sample stream to remove the target gas may be used as double checks for possible gas leaks before activating an alarm. Flame-emission-spectrometry monitors are not affected by humidity, air flow, or temperature. Commercially available systems have been perfected to the point where they can respond in only 2 s of sampling time. Calibration of such systems is recommended every six months. The latter procedure takes approximately 30 min with standards provided. (The primary manufacturer of this type of system is Telos Labs.)... 

Ongoing calibration will help to assure that the chamber is working properly over time. Calibration can be performed by placing a temperature and/or relative humidity standard inside the chamber (near the probe used by the chamber controller). 

ASTM 3894 [139] is the standard that tests the flammability of the specimen arranged as two walls only, each 1220 mm x 610 mm high, or two walls plus a ceiling 1220 mm X 610 mm high, or two walls plus a ceiling 1220 mm square, which are exposed to a premixed propane flame positioned in the lower corner. A specified temperature time calibration is specified, and results are assessed in terms of flame spread. Thermocouples are positioned at specified locations on the specimen surface, and the times to maximum temperatures and the maximum temperatures are recorded. 

---