1. Overview
This series of meters is categorized into the standard and thermocouple type. This manual is illustrated based on the thermocouple type.
This series of meters has the following functions:
- 100 mV, 30 V DC voltage measurement, 20 mA DC current measurement, and switching value measurement;
- 100 mV, 30 V DC voltage output, 20 mA DC current output and SIMULATE output;
- V, mA manual step output, automatic waveform output;
- Simultaneous display of V, mA and percentage;
- Loop detection function: It simultaneously provides the 24 V loop power supply and measures the current.
The following functions are added to the thermocouple type:
- Eight scale division (i.e., R, S, B, K, E, J, T and N) thermocouple measurement and output function;
- Temperature display in Celsius degree and Fahrenheit degree;
- Automatic and manual cold junction compensation function.
Figure 1: RuoShui 71B Signal Generator
2. Safety Warnings
The design, manufacturing and test of this meter all meet the safety standard requirements of IEC61010-1. The manual contains the warnings and safety rules that users must comply with to ensure the safe use of the meter and its safe status. Please read the following instructions before use.
Warning
- Do not use a damaged meter. Before using the meter, please check its enclosure to see if there is any crack, missing plastic part or if its outer protective cover is in place. Please pay special attention to the insulation layer of the joints.
- Please make sure that the battery cover is locked tightly before using the meter.
- Please remove the test leads from the meter before opening the battery cover.
- Check the test lead to see if its insulation has any damage or it has any exposed part. Check the connectivity of the test leads. If the lead is damaged, please replace it before using the meter.
- If the meter malfunctions, it means that the protection could have been damaged, so please do not use it. If there is any doubt, the meter should be sent for maintenance.
- Do not use the meter near explosive gases, steam or dust.
- The meter only uses 6LR61 batteries, so please make sure the battery is correctly installed.
- When using a test probe, the finger should hold the back of the probe's protective layer.
- When connecting wires, connect the common test leads first, and then connect the live test leads. When dismantling, remove the live test lead first.
- Please carefully read and understand the manual before using the meter.
- The requirements of the manual must be complied with at any time, and the manual should be well kept to ensure it available for reference at any time.
- During the meter test, incorrect operation may lead to accident and damage to the meter.
Cautions
To prevent damage to the meter caused by the tested equipment:
- The knob switch must be turned to the correct position of measurement range when conducting a measurement. The test lead and the tested circuit must be disconnected before turning the knob switch. It is strictly prohibited to switch the range during a measurement, to prevent damage to the meter.
- When the screen shows "OL" signal, do not use the meter.
- Do not store or use the meter in a high temperature, high humidity, combustible, explosive, or strong electromagnetic environment, or a place with excessive dew or direct exposure to sunlight.
- Do not use abrasives or solvents to clean the meter; please use a damp cloth or neutral detergent.
- When the meter is dampened, please dry it up before storing it.
Symbols
| Symbol | Meaning | Symbol | Meaning |
|---|---|---|---|
| ~ | AC | Grounding | |
| --- | DC | Double insulation | |
| ~--- | AC and DC | + | Battery |
| ! | Critical information |
3. Meter Panel Introduction
Figure 2: Front Panel Layout
| No. | Location | Knob Switch Function |
|---|---|---|
| ① | TC mV | DC millivolt (DCmV) measurement. Thermocouple type: TC measurement can be selected by pressing the button. |
| ② | V | DC voltage (DVC) measurement |
| ③ | Switching value measurement | |
| ④ | mA | DC current (DCmA) measurement |
| ⑤ | 24V LOOP mA | Loop current measurement (loop power supply) |
| ⑥ | SOURCE mA | Current output |
| ⑦ | SIMULATE mA | Analog transmitter |
| ⑧ | V | DC voltage (DCV) output |
| ⑨ | TC mV | DC millivolt (DCmV) output |
Display Screen
Figure 2-3 and Table 2-3 are the illustrations for the screen display.
Figure 3: Display Screen Indicators
| Display | Illustrations |
|---|---|
| + | Low battery |
| INPUT | The meter works in the measurement mode |
| OUTPUT | The meter works in the output mode |
| RUN | Start automatic waveform output |
| RJ-M | Manual cold junction compensation of thermocouple |
| RJ-A | Automatic cold junction compensation of thermocouple |
| -8.8.8.8. | Data display area |
| % | Percentages of voltage and current |
| KJRTSBEN | Thermocouple (TC) scale division |
4. Setup
Startup
To switch on the meter, please turn the knob switch to any of the function positions.
When the power is turned on, the meter starts an internal self-diagnosis with a full screen display before corresponding operations can be conducted.
To ensure correct live operation of the meter, the meter must be powered off for 5 seconds before restarting it.
Automatic Power Off
The factory setting of the meter: If the user does not perform any operation on the meter within 15 minutes, it will automatically turn off the power.
Once the meter automatically powers off, to restart it, please turn the knob switch to OFF position and then turn it on.
Users can set on their own whether to use the automatic power off function (Refer to Chapter IV "Setting Function").
Note: The meter will still consume about 1 mA current after it automatically turns off power, so it is recommended to turn the knob switch to the OFF position when not using it.
Turn on Back Light
Press the button 
continuously to turn on the back light, and press the button continuously again to turn it off.
Automatic Back Light off
The factory setting of the meter: If the user does not turn off the meter's back light within 30 seconds, the meter will automatically turn off the back light.
Users can set on their own whether to use the automatic back light off function (Refer to Chapter IV "Setting Function").
Battery Replacement
This meter uses one 9V (6LR61) alkaline battery. Please follow the following steps to replace the battery:
- Turn off the meter power and disconnect all test leads;
- Remove the screw on the battery box with a cross screwdriver, and remove the battery cover.
- Take off the old battery and fasten a new battery to the battery buckle. Then put it into the battery compartment;
- Put the battery in the lower case and tighten the screw.
Video: Unboxing, test leads, and battery compartment access.
Figure 4: Packaging Accessories
5. Operating Instructions
Measurement of DC Voltage
- Turn the knob switch to the white "V" or "TC mV" position;
- Insert the black probe into "COM" plughole and the red probe into "INPUT" plughole;
- Connect the probes to the circuit to be measured and read the measured value after stabilization.
| Displayed voltage value | Percentage display | |
|---|---|---|
| 0~10V | 1~5V | |
| 0.00V | 0.0% | -25.0% |
| 1.00V | 10.0% | 0.0% |
| 5.00V | 50.0% | 100.0% |
| 10.00V | 100.0% | 225.0% |
| 30.00V | 300.0% | 750.0% |
Measurement of Current
- Turn the knob switch to the white "mA" position;
- Insert the black probe into "COM" plughole and the red probe into "INPUT" plughole;
- Connect the probes to the circuit to be measured and read the measured value after stabilization.
| Displayed current value | Percentage display | |
|---|---|---|
| 4~20mA | 0~20mA | |
| 0.00mA | -25.0% | 0.0% |
| 4.00mA | 0.0% | 20.0% |
| 20.00mA | 100.0% | 100.0% |
| 22.00mA | 112.5% | 110.0% |
Measurement of Circuit Current (Loop Power Supply)
This function can be used to measure the flowing current when 24V constant DC is applied.
The 24V circuit measurement function can be used to measure the transmitter circuit.
(The meter can be connected to the transmitter instead of the signal regulator.)
Figure 5: Input Measurement Examples
Test of Switching Value
- Turn the knob switch to "
" position; - Insert the black probe into "COM" plughole and red probe into "INPUT" plughole;
- Connect the probes to the contacts on the switch to be tested. And display "OFF" (open) or "ON" (close) according to the status of the switch. When the test result is "ON", the buzzer will tweet. When the switch resistance exceeds 20kΩ, it is considered to be in an "OFF" status.
Measurement of Thermocouple
- Turn the knob switch to white "TC mV" position and select the corresponding scale division of thermocouple (TC).
- Insert the thermocouple into "COM" and "INPUT" plugholes. Ensure that the thermocouple plug with + symbol is inserted into "INPUT" plughole of the meter.
- Read the measurement result from the display.
The main display area shows the temperature value and the auxiliary display area shows the cold junction temperature value. Users can select automatic compensation (screen display RJ-A, automatic compensation once every 10 seconds) or manual compensation (screen display RJ-M) for cold junction temperature; or select to close cold junction compensation. Whether to open the cold junction compensation is up to the user himself (Refer to Chapter IV "Setting Function").
Use of Voltage Output Function
- Turn the knob switch to yellow "V" position or "TC mV" position;
- Insert the black probe into "COM" plughole and red probe into "OUTPUT" plughole;
- Connect the probes to the input end of user's meter;
- Press the button
or 
to select the output setting position; press the button or to change the value of setting position, which can increase or decrease automatically. Keep pressing the button, and the value can be changed consecutively after 1 second.
Use of Thermocouple Output Function
- Turn the knob switch to yellow "TC mV" position; press the button to select the corresponding scale division of thermocouple (TC);
- Insert the black probe into "COM" plughole and red probe into "OUTPUT" plughole;
- Connect the probes to the input end of user's meter;
- Press the button or to select the output setting position; press the button or to change the value of setting position, which can increase or decrease automatically. Keep pressing the button, and the value can be changed consecutively after 1 second.
The main display area displays the temperature setting value, and the auxiliary display area displays the cold junction temperature value. Users can select automatic compensation (screen display RJ-A, automatic compensation once every 10 seconds) or manual compensation (screen display RJ-M) for cold junction temperature; or select to close cold junction compensation. Whether to open the cold junction compensation is up to the user himself (Refer to Chapter IV "Setting Function").
Use of Current Output Function (SOURCE Mode)
This meter provides two output modes: SOURCE mode: Current is provided from the meter; SIMULATE mode (analog): The meter absorbs the current from the external voltage source.
Constant Current Output (SOURCE Mode)
- Turn the knob switch to the "SOURCE mA" position and the output is set as 0mA;
- Insert the black probe into "COM" plughole and red probe into "OUTPUT" plughole;
- Connect the lead wire to the circuit to be measured;
- Press the button or to select the output setting position; press the button or to change the value of setting position, which increase or decrease automatically. Keep pressing the button, and the value can be changed consecutively after 1 second.
Constant Current Output (SIMULATE Mode)
SIMULATE (analog) mode refers to simulation of a set of current circuit transmitters by using the meter. When the external DC voltage (5 to 28V) and the measured current circuit are in series, SIMULATE mode should be selected.
Warning
Before connecting test leads to current circuit, set the knob switch in some position of mA output first. Otherwise, the low impedance from other positions of the knob switch may occur in the circuit, resulting in the current up to 35mA flowing in the circuit.
Figure 6: Output Function Examples
Manual Step Output
Under 10V voltage and current output, press the button to select 25% or 100% manual step output function in turn, the screen shows: .
Press the button or to increase or decrease the voltage or current by 25% step or 100% step.
Different voltage and current span can be selected through this function. (Refer to Chapter IV "Setting Function")
| Voltage stepping | Output value | |
|---|---|---|
| 0~10V | 1~5V | |
| 0.0% | 0.00V | 1.00V |
| 25.0% | 2.50V | 2.00V |
| 50.0% | 5.00V | 3.00V |
| 75.0% | 7.50V | 4.00V |
| 100.0% | 10.00V | 5.00V |
| Current stepping | Output value | |
|---|---|---|
| 4~20mA | 0~20mA | |
| 0.0% | 4.00mA | 0.00mA |
| 25.0% | 8.00mA | 5.00mA |
| 50.0% | 12.00mA | 10.00mA |
| 75.0% | 16.00mA | 15.00mA |
| 100.0% | 20.00mA | 20.00mA |
Automatic Waveform Output
Under 10V voltage and current output, press the button to select the automatic waveform output function with the screen display: A, and at the same time display the default output set value and output the corresponding signal.
Press the button or to start or stop automatic waveform output. If automatic waveform output is started, the screen displays the "RUN" character; if the automatic waveform output is stopped, the output will remain at the current value.
Different voltage and current span can be selected through this function. (Refer to Chapter IV "Setting Function")
6. Setting Function
To enter the meter setup, press the button under the meter shutdown status, and then turn the knob switch to any non-OFF position. In the setup mode, the screen's auxiliary display area displays the settings, and the main display area shows the factory default values. Press the button to change the settings; press the button continuously to save the settings (the main display area shows SAVE, indicating that this setting has been saved). When the setup is completed, turn off the machine.
| Settings | Function | Default Values |
|---|---|---|
| APOF Automatic shutdown | ON or OFF. Press the button or to select. | ON |
| BLOF Automatic off backlight | ON or OFF. Press the button or to select. | ON |
| IPCE Current span | 4-20 or 0-20. Press the button or to select. | 4-20 |
| UPCE Voltage span | 0-10 or 1-05. Press the button or to select. | 0-10 |
| TEMP Temperature unit | °C or °F. Press the button or to select. | °C |
| RJ-ON Cold junction compensation of thermocouple | ON or OFF. Press the button or to select. | ON |
| RJ-SET Cold-junction compensation method | Automatic (AUTO) or manual operation (MANUAL). Press the button or to select. | AUTO |
| RJ-TEMP Temperature on the manual cold junction | -10.0°C~50.0°C (0.0°F~122.0°F). Press the button or for the setting position; press the button or to change the setting position value. | 23.0 |
| FACE Return to the factory default value | Press the button continuously, and the main display area displays SAVE, indicating that it has returned to the factory default value. |
7. General Maintenance
- Clean the meter enclosure on a regular basis with a damp cloth and mild detergent. Do not use abrasives or solvents.
- If the battery isn't used for a long time, it shall be taken out.
- Dirt or wet air on the plughole can affect the reading.
Please follow the following steps to clean the connection port:
- Turn off the meter power and dismantle all test leads;
- Clean the dirt on the connection port;
- Clean each connection port with a new cotton swab dipped in alcohol.
8. Specifications
General Characteristics
| Characteristic | Value |
|---|---|
| Display refresh | 2~3 times/second |
| Overload protection | 50mA/30V |
| Working temperature and humidity range | 0~40 °C and a relative humidity below 85% (no condensation) |
| Storage temperature and humidity range | -20 °C~60 °C and a relative humidity below 90% (no condensation) |
| Precision ensures the temperature and humidity range | 23±5°C and a relative humidity below 75% (no condensation) |
| Temperature coefficient | 0.1 × basic precision/°C (temperature range <18 °C or >28 °C) |
| Ambient conditions for use | Indoor and outdoor use (not waterproof), with an elevation of 0~2000 m |
| Outrange display | OL |
| Battery kind | 9V (6LR61) alkaline battery one |
| Power consumption | When alkaline battery is used: Loop current measurement and DC current output (SOURCE) 20mA (a load of 1000Ω): approx. 1000mVA. Other work function: approx. 300mVA |
| Low battery | Display battery sign |
| Automatic shutdown | No operation for about 15 min by default |
| Preheating time | 10 min |
| Close the meter enclosure for calibration | No need for internal adjustment |
| Size | 147(L)×75(W)×42(D)mm |
| Weight | Approx. 230 g |
| Calibration cycle | One year |
Detailed Precision Index of Measurement
The accuracy is determined within one year after calibration when the operating temperature is 23 ± 5 °C, and the relative humidity is 75%.
The precision range can be marked as: ± ([% of the reading]+ count) (Note: "count" represents the increased or decreased number of the minimum effective digit).
| Measurement Function | Range | Measure Range | Resolution | Accuracy | Notes |
|---|---|---|---|---|---|
| DC voltage | 100mV | -10.0mV~110.0mV | 100uV | 0.2%+4 |
|
| 30V | -5.00V~30.00V | 10mV | 0.2%+4 | ||
| DC current | 20mA | 0.00mA~22.00mA | 0.01mA | 0.2%+4 |
|
| Thermocouple | R | 0°C~1760°C | 1°C | 0.2%+4 | Thermocouple measurement adopts ITS-90 thermometric scale, whose precision does not include error of the cold junction compensation, and the impact of thermoelectrical potential |
| S | 0°C~1760°C | ||||
| B | 400°C~1820 °C | ||||
| K | -200°C~1370°C | ||||
| E | -200°C~1000°C | ||||
| J | -200°C~1200°C | ||||
| T | -200°C~400°C | ||||
| N | -200°C~1300 °C |
Detailed Precision Index of Output
| Output Function | Range | Output Setting Range | Resolution | Accuracy | Notes |
|---|---|---|---|---|---|
| DC voltage | 100mV | 0.0mV~110.0mV | 100uV | 0.2%+4 |
|
| 10V | 0.00V~11.00V | 10mV | 0.2%+4 | ||
| DC current | 20mA | 0.00~22.00mA | 0.01mA | 0.2%+4 | 20mA maximum load: 1KΩ |
| Analog transmitter SIMULATE | -20mA | 0.00~-22.00mA | 0.001mA | 0.2%+4 |
|
| Loop power supply LOOP | 24V | ±10% | Maximum output current 25mA | ||
| Thermocouple | R | 0°C~1760°C | 1°C | 0.2%+4 | Thermocouple measurement adopts ITS-90 thermometric scale, whose precision does not include error of the cold junction compensation, and the impact of thermoelectrical potential |
| S | 0°C~1760 °C | ||||
| B | 400°C~1800°C | ||||
| K | 0°C~1350°C | ||||
| E | 0°C~700°C | ||||
| J | 0°C~950°C | ||||
| T | 0°C~400°C | ||||
| N | 0°C~1300°C |
Capacitive load≥0.01uF
9. User Tips
- Always refer to the detailed instructions in this manual for specific measurement and output procedures to ensure accurate and safe operation.
- Before any operation, ensure the device is powered off and test leads are properly connected or disconnected as required.
- For optimal performance and longevity, store the device in a clean, dry environment away from extreme temperatures and humidity.
10. Warranty and Support
Warranty & Guarantee
- We offer 100% genuine original RuoShui (Victor) instruments.
- 1 Year warranty for all of our products. (Excluding item damaged and/or misused after receipt. Accessories come with 3-month warranty.)
- We will bear all the shipping cost if the product is not as advertised, otherwise, Buyer shall pay the shipping cost.
- Defective items must be reported and returned within the warranty period (and in the original packaging, if possible)
Other Terms & Conditions
- If there is any problem with your order, Please do not contact us first, we will try our best to give you the best solution. Please don't give negative feedback before contact us, that won't help to solve your problem.
- No battery will be sent the product due to safety reason.
- We are not responsible for any custom duty or import tax.
Notes for Use of This Manual
This manual is subject to variation without prior notice.
The content of this manual is supposed to be correct. If the customer detects any mistake, omission, etc., please contact the manufacturer.
Our company does not undertake any responsibility for accidents or hazards caused by incorrect operations of the user.
The functions described in this manual do not be used as grounds for using the product for special purposes.
For further assistance, please refer to the official user manual PDF: View User Manual (PDF)