## measuring REN

### measuring REN

How do I measure REN for all phones on a line? Do I call the phone line and measure voltage and current when it rings to find the impedance? I suppose that would give me |Z|.

(in the US, 6930Ω resistor in series with an 8 µF is 1 REN)

(in the US, 6930Ω resistor in series with an 8 µF is 1 REN)

### Re: measuring REN

REN number is usually on the bottom of every phone.

On cordless there is one number, for the base.

Wayne

On cordless there is one number, for the base.

Wayne

### Re: measuring REN

this number is only relevant if you have older, solonoid type ringers..all new phone equipment use solid state ringers with REN < 1

### Re: measuring REN

This is not related to the question asked. Please stay on topic. The question is: how does one measure REN?WayneDsr wrote:REN number is usually on the bottom of every phone.

On cordless there is one number, for the base.

I think the simple answer is this:

(1)Measure the voltage when ringing.

get something around 70-90 VAC

(2)Measure current. when ringing

get something around 10-100 mA AC. For this example, let's assume 50mA AC.

(3) measure ring frequency (or assume US standard of 20Hz)

get 20Hz in the USA

(4) plug voltage and frequency into the USA equation for REN:

(90 volts) / ((6930 ohm) + (j / (2 * pi * (20 hz) * (8e-6 F))))

(5) Calculate and get current out:

(90 volts) / ((6930 ohm) + (j / (2 * pi * (20 hz) * (8e-6 F)))) = 0.0127248411 - 0.00182649834 j amperes

(6) calculate magnitude of current/REN.

|current| = ~13mA for one REN

(7) take the measurement for line current when ringing and divide by current/REN:

50mA/13mA= 3.8 REN

Last edited by jm9496 on Thu Aug 20, 2009 5:53 am, edited 2 times in total.

### Re: measuring REN

I used a scale but was fooled by it because it was in Celsius. So then I changed it to Imperial metric and now it measures REN just fine. Unfortunately It can only measure 2 REN's at a time.

Ooma Telo, Hub.

1958 was a very good year!

No cell phone , no land line- just Ooma

all my eggs in one Ooma basket

I lied- my wife has a cell, but not me!! I like my privacy and not being attached to a phone.

1958 was a very good year!

No cell phone , no land line- just Ooma

all my eggs in one Ooma basket

I lied- my wife has a cell, but not me!! I like my privacy and not being attached to a phone.

### Re: measuring REN

...unfortunately It can only measure 2 REN's at a time...

In order to measure more than 2 RENs at a time you need a Stimpy

Last edited by niknak on Thu Aug 20, 2009 7:24 am, edited 1 time in total.

### Re: measuring REN

REN number is usually on the bottom of every phone.

On cordless there is one number, for the base.

This may have not been the anwser you were looking for, but HARDLY off topic.This is not related to the question asked. Please stay on topic. The question is: how does one measure REN?

I was merely trying to answer your question about REN, easy answer, look on the bottom of the phone. This question has been asked many times in this forum and "bottom of the phone" has been the solution.

Until, now, of course.....

1 REN is equivalent to a 6930Ω resistor in series with an 8 µF (microfarad) capacitor.

Wayne

### Re: measuring REN

I had a stimpy but was crushed by a garbage truck.

Ooma Telo, Hub.

1958 was a very good year!

No cell phone , no land line- just Ooma

all my eggs in one Ooma basket

I lied- my wife has a cell, but not me!! I like my privacy and not being attached to a phone.

1958 was a very good year!

No cell phone , no land line- just Ooma

all my eggs in one Ooma basket

I lied- my wife has a cell, but not me!! I like my privacy and not being attached to a phone.

### Re: measuring REN

just4fn, niknak

HA HA You guys crack me up!

Wayne

HA HA You guys crack me up!

Wayne

- southsound
**Posts:**3519**Joined:**Fri Feb 06, 2009 11:31 am**Location:**Harstine Island, WA

### Re: measuring REN

The resident raccoon normally stays out of discussions beyond his comprehension but one could assume that an answer with the most formulae and decimal places would be nearer to the correct one as it is analytically self-contained. The more simplistic approach used postal scales to compare REN's and Stimpy's contains flawed logic. The basic problem with comparison of mass is that the expression and/or existence of any difference relation entails a common medium and syntax. Reality is a relation, and every relation is a syndiffeonic relation exhibiting syndiffeonesis or "difference-in-sameness". Therefore, reality is a syndiffeonic relation. Syndiffeonesis implies that any assertion to the effect that two things are different implies that they are reductively the same; if their difference is real, then they both reduce to a common reality and are to that extent similar. Syndiffeonesis, the most general of all reductive principles, forms the basis of a new view of the relational structure of reality..

Therefore, the following may be more nearly correct:

Therefore, the following may be more nearly correct:

(90 volts) / ((6930 ohm) + (j / (2 * pi * (20 hz) * (8e-6 F)))) = 0.0127248411 - 0.00182649834 j amperes

ooma customer since February 2009

VoIP hardware: 2 Telo w/3 handsets & Linx / ooma core

Total Lines: 8 / Numbers: 11 / Handsets: 20

Lifetime Premier Member

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VoIP hardware: 2 Telo w/3 handsets & Linx / ooma core

Total Lines: 8 / Numbers: 11 / Handsets: 20

Lifetime Premier Member

Friends don't remember what Landline Integration was or why we did it.