P-SOP0804-3262-E02
2/5
Standard Operating
Procedure
（
SOP
）
Automatic digital
Refractometer
RX-7000
α
(alpha)
2. Daily Check
Turn on the power supply switch. After checking the initial screen (opening message) and
also checking the present temperature in the measurement display screen, perform zero
adjustment with distilled water. The RX-
7000α can be used by performing
zero adjustment
with distilled water as a daily check. (Although, it is not necessary to perform zero
adjustment after each measurement. It is recommended to perform reference point
adjustment again when the refractometer has not been used for an interval of more than one
hour.)
*Zero adjustment is the operation to confirm the standard point (zero point) of the refractive
index in the RX-
7000α
. If zero point is confirmed by the calculation software of the
refractometer, that is all for calibrating all measuring spans.
3. Periodical Inspection
Inspect the RX-
7000α
with standard sucrose solution once a month to see if it indicates the
measured value correctly.
Select a concentration point which you often measure and use this as a reference for
inspection.
Save the checked data and record.
3-1. Inspection by Brix (standard sucrose solution)
Make a standard sucrose solution of 10.00%, 30.00%, and 50.00% correctly, and measure
them. Confirm that the measured value coincides with each standard sucrose solution.
(The method of making the standard sucrose solution is written in [data 1] of the
introduction for validation.).
Record of Periodical inspection
Distilled water
(0.00%)
Brix 10.00%
Brix 30.00%
Brix 50.00%
1st measurement
2nd measurement
3rd measurement
Caution
Measure at room temperature of 18.0 to 22.0
℃
.
Be sure to set the targeted temperature of the RX-
7000α to 20.00
℃
.
