TRIPLETT RHT45 Digital Psychrometer User Manual

RHT45Digital Psychrometer

User Manual

Introduction

Congratulations on your purchase of the Triplett RHT45 Digital Psychrometer. This meter serves as a very valuable HVAC diagnostic tool.It measures wet bulb (WB), dry bulb (DB), percent relative humidity (RH%), and dew point (DP) which allows for quick and easy diagnostic of airflow problems. Specialized modes include NORMAL Psychrometer Mode, Target Superheat Mode (TSH), and Target Evaporator Exit Temperature Mode (TEET).

Safety

• Do not operate the meter in environments where the following are present: explosive gases (or materials), combustible gases (or materials), steam, or dust.
• Please replace the battery immediately when the low battery symbol appears on the LCD.
• Do not touch the meter’s circuit board for any reason; static electricity or contamination could damage the sensitive components.
• This instrument was designed for pollution degree 2. Operation Altitude: Up to 2000m (7000’).

Description

Display

How it Works:

This meter has three sensors. One for RH% and two for temperature.Depending on where you place these sensors and how you set up the meter.The meter will display the measurements and the results of calculations from these inputs.Inside the ‘cage’ on the top of the meter is a thermistor, right next to the RH% sensor. It’s used to measure ambient air(DB).In addition to the thermistor, a thermocouple can be plugged into the temperatures (including wet bulb) in hard-to-reach places. such as in the front or in the back of the evaporator coil.To use this meter, you must tell it what test you want it to perform. Select the parameter you want to measure, and choose which temperature sensor to use, either the thermocouple (T/C) or the ‘caged’ thermistor (NTC). Take your measurements. Read the results, both the directly measured readings, and the calculated results.

Operation

Normal Psychrometer Mode

• Turn the Meter ON by pressing the button, Select NORM by pressing the “MODE” button until NORM is displayed on the LCD.
• Press the “SENSOR” button and hold for 2s to select temperature sensor: T/C for thermocouple, NTC for sensors in the ‘cage’.
• For T/C, the display will show the temperature. For NTC, press the “SENSOR” button to select RH, DP, WB, DB mode, and the desired icon (RH,DP,WB,DB) is displayed. Then read the display.

Target Superheat Mode(TSH)

1. Turn the Meter ON by pressing the button, Select TSH by pressing the “MODE” button until TSH is displayed on the LCD.* Note: blinking numbers mean you are seeing real-time measurements. Non-blinking means the reading has been ‘locked in ’.Press ENTER button to unlock and take a new reading. *
2. The more accurate method:a. Wet the thermocouple A.Clip it to the front of the evaporator coil. Plug it into the top of the meter. Make sure the display show ID and WB. If not, press the “SENSOR” button. Press and hold the “SENSOR” button until T/C is displayed. Once the reading is stable, press ENTER button.b. Unplug thermocouple A and plugin thermocouple B.c. Clip the thermocouple B to the side of the condenser. Press the “SENSOR” button until OD and DB are displayed. Once the reading is stable, press ENTER.*Note: for DB, you can put the ‘cage’ sensors in front of the condenser and select NTC if that is easier.The easy way: While the numbers are blinking, press and hold the “SENSOR” button until NTC is displayed. Press the “SENSOR” button until WB or DB is displayed. When WB is displayed, place the ’cage’ sensors in front of the indoor return and press ENTER button once the reading is stable.When DB is displayed, put the ‘cage’ sensors in front of the condenser and press ENTER button when the reading is stable.*
3. Press the OUTPUT button to display Target Superheat.
4. Compare Target Superheat to Actual Superheat.
5. Adjust refrigerant levels accordingly for a fixed restrictor system. If Actual Superheat is higher than Target Superheat, add refrigerant. If Actual Superheat is lower than Target Superheat, recover refrigerant.

Target Evaporator Exit Temperature (TEET)

1. Turn the Meter ON by pressing the button, Select TEET by pressing the “MODE” button until TEET is displayed on the LCD.Note: blinking numbers mean you are seeing real-time measurements. Non-blinking means the reading has been ‘locked in ‘.Press ENTER button to unlock and take a new reading.
2. Wet the thermocouple A wet sock thermocouple and clip both thermocouples (thermocouple A and thermocouple B) in front of the evaporator.
3. Plug the thermocouple A into the top of the meter.Note: If “OL” is displayed, then the measurements are out of range. Retake the temperature measurements and ensure the temperature inputs are correct.
4. Press the “SENSOR” button until WB is displayed. Press and hold the “SENSOR” button until TIC is displayed. When reading is stable, press ENTER
5. Unplug thermocouple A and plug in thermocouple B.
6. Press the “SENSOR” button until DB is displayed. Press and hold the “SENSOR” button until TIC is displayed. When reading is stable, press ENTER button
7. Press the OUTPUT button and read Target Evaporator Exit Temperature. Note: If “OL” is displayed, then the measurements are out of range. Retake the temperature measurements and ensure the temperature inputs are correct.
8. Compare Target Evaporator Exit Temperature to Actual Evaporator Exit The Actual Evaporator Exit Temperature is the measured temperature of the air after it has passed through the evaporator.
9. Adjust airflow accordingly. An Actual Evaporator Exit Temperature. That is below the Target Evaporator Exit Temperature. It indicates a low airflow. Increasing airflow can be accomplished by eliminating restrictions in the duct system, increasing blower speed, cleaning filters, or opening registers. An Actual Evaporator Exit Temperature that is above the Evaporator Exit Temperature .usually indicates low capacity. Occasionally airflow is higher than expected. Look for causes of low capacity such as refrigerant mischarge or a dirty condenser coil. If the airflow is high, correct it by lowering the fan speed.Note: If “OL” is displayed, then the measurements are out of range. Retake the temperature measurements and ensure the temperature inputs are correct.

IMPORTANT TO NOTE:

Because everything within the system is interdependent, one adjustment can affect other parts of the system. For example, increasing airflow increases the superheat, which may require adding refrigerant. After any modifications, allow 15 minutes to stabilize and then retest. For the best results take measurements right after each other.Select °C or °FTurn the Meter ON by pressing the button, Select °C or °F by pressing the °C/°F” button until °C or °F is displayed on the LCD. Press and hold the °C/°F” button for 2s to select backlight on or off.Auto-Power-Off (APO)This meter shall enter a sleep mode after 15 minutes of inactivity, Pressing the “MAX/MAIN” button while turning the meter from OFF to ON shall cause the APO to be disabled, and the APO icon to be turned off.

Battery replacement

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WARNINGIf the symbol “appears on the LCD, please replace the battery immediately

• Turn off the instrument.
• Remove the battery cover
• Replace the battery.
• Install the battery cover

Specifications

Warranty Information

Triplett / Jewell Instruments extends the following warranty to the original purchaser of these goods for use. Triplett warrants to the original purchaser for use that the products sold by it will be free from defects in workmanship and material for a period of (1) one year from the date of purchase. This warranty does not apply to any of our products that have been repaired or altered by unauthorized persons in any way or purchased from unauthorized distributors so as, in our sole judgment, to injure their stability or reliability, or which have been subject to misuse, abuse, misapplication, negligence, accident or which have had the serial numbers altered, defaced, or removed. Accessories, including batteries, are not covered by this warranty

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