Rinstrum - R300 Series Digital Indicator Operator Manual Rev 1.5 
Page 4 
 
1. Introduction 
The Rinstrum R300 Series are precision digital indicators using 
the latest Sigma-Delta A/D technology to ensure fast and 
accurate weight readings.  
This manual contains information on the operation of the R310, 
R320 and R321.   
Note: The R321 is the R320 enclosed in a stainless steel 
housing.  In this manual any reference to the R320 includes the 
R321. 
Unless otherwise indicated, all information will apply to the 
R310, R320 and R321.  For the purposes of readability, where 
all instruments are being described, they will be referred to as 
the R300 Series.   
1.1. Approvals 
• NSC approval (4000 divisions at 0.8µV/division).  
• NMI approval (4000 divisions at 0.8µV/division).   
• C-tick approved and CE approved.   
1.2. Features 
• R310 has Zero and Tare functionality. 
• R320 has Zero and Tare functionality as well as battery 
backed clock/calendar, special function key (for counting, live 
weight averaging, peak-hold, etc.). 
1.3. Manuals 
For more information on the R300 Series refer to the R300 
Series Reference Manual, R300 Series Quick Start Manual 
and R300 Series Communications Manual (available free of 
charge from www.rinstrum.com
).