6
Precision
is how closely repeated measurements
agree with each other. Precision is usually
expressed as standard deviation (SD).
Accuracy
is defined as the nearness of a test result
to the true value.
Although good precision suggests good accuracy,
precise results can be inaccurate. The figure
explains these definitions.
In a laboratory using a standard solution of
1.00 mg/L phosphate and a representative lot
of reagent, an operator obtained with a single
instrument a standard deviation of 0.03 mg/L.
SPECIFICA
TIONS
Range
0.00 to 2.50 mg/L
Resolution
0.01 mg/L
Accuracy
@25
°
C (77
°
F)
±0.04 mg/L ± 4% of reading
Light Source
Tungsten lamp
Light Detector
Silicon Photocell with narrow band interference filter @610 nm
Method
Adaptation of the ascorbic acid method. The reaction between phosphate and
the reagent causes a blue tint in the sample.
Environment
0 to 50
°
C (32 to 122
°
F)
max 95 % RH non‑condensing
Battery Type
9V (1 pc.)
Auto‑Shut off
After 10’ of non‑use in measurement mode; after 1 hour of non‑use in
calibration mode; with last reading reminder
Dimensions
192 x 104 x 69 mm (7.6 x 4.1 x 2.7”)
Weight
320 g (11.3 oz.)
REQUIRED REAGENTS
Code
Description
Quantity/test
HI93713‑0
Powder Reagent
1 packet
PRECISION AND ACCURACY
