Instrument Specifications; Intended Use; Operating Specifications; Environmental Specifications - Chrono-Log 490 4+4 Instruction Manual

needed for testing. If the light transmission difference between
the test and reference samples is insufficient for accurate testing,
the aggregation output cycles continuously between the baselines
to warn the operator and a Range Error will be indicated on the
front panel.
When a stimulus is added to the cuvette containing PRP and the
platelets respond, changes in light transmission occur and are
recorded over time by the recording device.
PRP, which is turbid, is stirred in a test cuvette maintained at
37° C. The light transmittance through this turbid sample is
measured relative to the PPP blank. When the agonist is added,
the platelets will form increasingly larger aggregates and the PRP
will begin to clear, allowing more light to pass through. This
increase in light transmittance is directly proportional to the
amount of aggregation and is amplified and recorded as a signal
on chart paper or digitized into a computer using AGGRO/LINK®
TM
Opti8 Software.
When the platelets undergo shape change in response to a
stimulus (agonist; aggregating agent), their larger size allows less
light to pass through the PRP: this is recorded as less light
transmission through the sample relative to the PPP. If the dose
of aggregating agent is strong enough to cause the platelets to
adhere to each other and form aggregates, more light is able to
pass through the PRP sample. The change in light transmission
recorded, over time, shows a trend towards the platelet poor
plasma, or 100% light transmission. In-vitro aggregation
recordings are characterized by their appearances:
• shape change
• a first wave of aggregation (primary aggregation) that may
reverse and return towards the PRP baseline
• Irreversible second wave aggregation that occurs when the
platelets' secreted granule contents become the stimulus
and cause additional aggregation.
Aggregation curves are also characterized by:
• the maximum amount of change in light transmission caused
by the agonist (percent aggregation)
• the slope, or rate of aggregation, reported in % of
aggregation per minute.
Multiple aggregating agents and concentrations are usually used
to stimulate the platelets. Different aggregating agents stimulate
different pathways of activation in the platelets: either binding
sites or metabolic pathways. Different concentrations of agonists
are used to elicit a family of curves (dose response curves).
The pattern of responses to these test panels is compared to
established normal response patterns and established abnormal
response patterns. This information is considered to relate to the
platelet function component of hemostasis.
CHRONO-LOG® MODEL 490 4+, 490 4+4
AGGREGATION SYSTEM INSTRUMENT
SPECIFICATIONS

Intended Use

The CHRONO-LOG® Model 490 4+4 Aggregometer is intended for
use for in-vitro diagnostic use for measuring Platelet Aggregation
in Platelet Rich Plasma. This device is intended to be used in a
clinical laboratory environment by laboratory technicians. For use
Document # 49044IM1
Revision 7.5
Dated February 16, 2017
only with light transmission aggregometry assays cleared for use
with the CHRONO-LOG® Platelet Aggregometry systems.

Operating Specifications

• Display - Liquid Crystal Display (LCD) unit with a 24 character
by 2-line capability. The LCD displays the actual
temperature in degrees Celsius, stirring in RPM's,
PPP/reference Select, and calibration mode and warning
messages.
• Heater Block - Electronically controlled heater block can be
set between 35.0°C and 39.0°C in 0.1°C steps. Both the
temperature setting and actual temperature of heater block
are displayed on front panel. Operation is prevented while
temperature is outside ±0.2°C of the temperature setting.
Stirrer - Nine stirring speeds from 400 RPM to 1200 RPM in
•
100 RPM steps and a stirrer stopped position. The selected
stirring speed is displayed on the front panel. Stirrer speed
accuracy is better than 0.01%. There is a feature that
prevents operation if stirrer is not within ± 10 RPM of the
selected setting.
• Optical/Aggregation/Turbidometric - Automatic baseline
setting from a front panel push button with an over-range
detection to prevent operation if baseline does not set.
• Output resistance for analog output - Less than 10,000
ohms.
Computer Interface – USB
•
• Power requirements - 115 or 230VAC; 50 or 60 Hz 60 watts
max. The main supply voltage fluctuations are not to exceed
10% of the nominal supply voltage.
Fuse – For 115 VAC: 630 mA, 250V; Time lag, 5x20mm or
•
equivalent; For 230 VAC: 315 mA 250V, Time Lag, 5x20mm
or equivalent.
• For continued protection only the correct stated fuse values
may be used. Failure to use the correct value may result in a
hazard.
• DIN input connector for an eight (8) channel configuration.

Environmental Specifications

Caution – This Instrument is intended for indoor use only.
Failure to operate in a protected environment in accordance
with instructions may present a shock hazard. Use of the
instrument in a manner contrary to manufacturer guidelines
may result in protection impairment.
• Operating Temperature: 15° to 30° C (60° to 86° F)
• Storage Temperature: -20° to 60° C (-4° to 140° F)
Relative Humidity: 5% to 85% (Noncondensing)
•
• Operating Altitude: -16 to 2000 M (-50 to 6,560 ft.)
Storage Altitude: -16 to 10,600 M (-50 to 35,000 ft.)
•

General

• Four (4) Channels [One, 4-Channel Module] or Eight (8)
Channels [Two, 4-Channel Modules] with connecting cable
• Sample Volume - 500 µL or 250 µL [spacer not required for
micro-volume testing]
Cuvettes - P/N 312
•
• Stir Bars - reusable teflon coated P/N 313, disposable P/N
311
• Incubation Wells – two (2) wells for each channel for P/N
312 cuvettes at 36.5° ± 1.0°C.
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